Kathryn Joanne Dixon

The brutal murder of mother, wife and computer expert Pamela Vitale October 15, 2005 became an instant international news story.  Vitale's husband Daniel Horowitz was a television personality and the attorney in the high profile case of Susan Polk who was accused of killing her husband psychologist Felix Polk.  Both the Polk home and the Vitale/Horowitz home were located in Contra Costa County less then ten miles apart.

On October 19, 2005 16-year-old neighbor Scott Dyleski was arrested and charged as an adult in the Vitale murder during a residential robbery making him eligible for life in prison without parole.  He has pled not guilty to the crimes.

Hal Jewitt, a 24 year veteran of the District Attorney's office will prosecute the case.  Scott Dyleski will be defended by Ellen Leonida who has been with the Contra Costa Public Defender's office for nine years.  Superior Court Judge Barbara Zuniga, very experienced in conducting murder trials, will preside over the Dyleski trial.  Judge Zuniga has ruled against a change of venue by the defense but has left the door open for additional arguments on the subject in the event additional evidence is introduced.  Zuniga has also ruled that the jury may not hear the audio of Daniel Horowitz's 911 call after finding his wife's bludgeoned body.  Opening arguments begin on July 27, 2006.

No eyewitnesses to the murder have been located if any exist.  DNA will play a crucial role in the murder trial.

A prosecutor's duty is to connect a suspect's DNA to the crime if the facts so warrant.  Did Deputy D.A. Hal Jewitt establish at the preliminary hearing that probable cause existed that in order to hold Scott Dyleski over for trial?  According to the preliminary hearing judge Mary Ann O'Malley, the answer is yes. She made this finding at the conclusion of the preliminary hearing on February 17, 2006.  On March 3, 2006 Dyleski was arraigned for the murder of Pamela Vitale.

The jury, however, is required to employ a higher standard of proof than that used at the preliminary hearing.  When the jury rules on the DNA evidence the prosecution must establish proof beyond a reasonable doubt.

What will the defendant face?  What will the jury hear?  Through the looking glass of the preliminary hearing a preview of the trial based on DNA evidence emerges.

But as Dr. Henry Lee would say, "Something wrong."

At the preliminary hearing, issues of reasonable doubt and even possible third party culpability emerged when prosecutor Hal Jewitt called two expert witnesses to the stand.  At this point the DNA evidence was not fully attacked by the defense, except by some cross-examination.

On June 9, 2006, public defender Ellen Leonida made a Kelly-Frye motion regarding a type of DNA evidence test called Y-STR. A ruling on this motion is pending.  A Kelly-Frey motion is based on contentions that the scientific evidence at issue is novel and has not gained "general acceptance" in the relevant field according to scientific experts.  Therefore it should be rejected by the court.  If evidence passes the Kelly-Frye test, later, at trial, the defense may also object as to the reliability, relevance and materiality of the evidence.  Defense attorneys may also produce their own scientific experts and even re-test some DNA samples.  The Defense may also allege evidence "planting" and/or crime scene "staging".  "Planting" is a type of negligence or misconduct by parties who place evidence at a crime scene.  "Staging" involves people who set up a crime scene so as to give a desired impression of the nature of the  crime and perpetrators involved.

Of utmost importance in the Dyleski case will be issues of DNA contamination or transference.

At the preliminary hearing DA Jewitt tried to show Dyleski's DNA was on the body of the deceased at the crime scene.  If that could be proven Jewitt's case would be a slam dunk.  The rest of the evidence against Dyleski is largely circumstantial.

Testimony was given by an immunized witness and co-conspirator Robin Croen who was involved with Dyleski is a credit card scheme involving a potential marijuana growing business.  Computer entries support Croen's contentions including attempts by Dyleski to have hydroponic equipment delivered to the Horowitz/Vitale address.  This effort was thwarted by a sales person who told Dyleski shortly before the murder that the company would not deliver the equipment.  So, although Dyleski's alleged motive has not yet been established Vitale's home was targeted by Dyleski in the scheme he was involved in with Robin Croen.

Aside from this scheme there is no evidence of criminal behavior in Dyleski's background.  It is an evidentiary leap from a pot and credit card scheme to conduct that resulted in the cruel, brutal, depraved of  Pamela Vitale.  Perhaps because of this reason DA Jewitt emphasize Dyleski adolescent interest in both cloths and bizarre drawings.  During the preliminary DA Jewitt introduced as evidence a swab of Pamela Vitale's blood obtained from her right foot at the crime scene.  Jewitt attempted to connect foreign DNA material found in that swab to Dyleski.

Did he succeed? That depends on the Yfiler, the machine used to analyze the Y-STR process.

The Contra Costa County Sheriff's department is on the frontier of forensic science.  The department used a research lab employing the Yfiler to conduct a novel forensic test on this swab.  The sheriff's forensic criminalist also used Polymerase Chain Reaction (PCR) to amplify the small DNA sample into a larger sample.  The larger sample enabled the technician to the DNA  code at various loci or markers.

This article will first address the results of this Yfiler test, and then will examine the other stains and DNA tests the prosecution revealed during the preliminary hearing.

First, the Yfiler test. 

DA Jewitt tried to show that the blood on the sole of Pamela Vitale's right foot contained a mixture of her own blood and biological material containing the DNA of Scott Dyleski.  The forensic theory, not stated explicitly but strongly implied by Jewitt, was that Dyleski shed blood, saliva, sweat or skin upon the bleeding foot of Ms. Vitale during the brutal murder.  To prove this, the prosecutor called Gary C. Harmor to the stand.

Harmor was quickly qualified to testify as an expert in the field of serology. He is a Senior Forensic Serologist employed by the Serological Research Institute in Richmond, California. He is an expert in YSTR - "Short Tandem Repeat of the Y chromosome.

Harmor received the sample labeled 3-10 along with a blank control sample from David C. Stockwell.  Stockwell is a Senior Criminalist employed by the Contra Costa County Sheriff's criminalist lab in Martinez. 3-10 was the UNKNOWN SAMPLE, an extraction of liquid from the blood on Vitale's foot. Harmor also received sample 12-1, a REFERENCE SAMPLE.  This sample was an oral swap taken from Scott Dyleski after his arrest, along with an accompanying blank control sample.

Harmor testimony stated that he had used the Yfiler to establish that all 17 markers profiled matched when he compared Unknown Sample 3-10 to Reference Sample 12-1.

As explained by Applied Biosystems in its December 6, 2004 press release for its new product Yfiler:

The Yfiler assay co-amplifies 17 Y-chromosome STR regions in a single PCR reaction. STRs are repeated DNA sequences that are variable in length and are widespread throughout the human genome. Such variability allows discrimination among individuals in a population...

What did this match of 17 Y-chromosome STR regions or markers mean?

Harmon testified he tried to compare profiled markers in 3-10 to profiles on 1) an Internet data base, 2) an internal data base, 3) the company's database.  There were no matches between S-10 and any of the profiles on any of these data bases.

The data bases were profiles (or haplotypes) of males of all races which have been collected so far. If S-10 had matched a profile in one of these data bases,  Harmon would have been able to show how many matches there were among other profiles representing a mean frequency across all haplotypes sampled in each data base. Mean frequency would be expressed in terms a jury could try to understand - for example 1 in 159 or 1 in 12,000.)  No mean frequency was found for Dyleski's sample.

Harmon, however, did not give up.  After noting that the 3-10 sample could only be from a male source, that is, from the Y chromosome which only males have, he stated that the DNA would certainly be in the DNA of Dyleski's male line, such as his father and grandfather.  He stated the Yfiler test is better for exclusion than inclusion.  If the explanation is left at that, a jury could say that Dyleski himself could not be excluded from contributing biological material to that blood stain found on Vitale's foot.

But what can be included?  The entire patrilineal bloodline of Dyleski going back to the origins of man would be included.  Surnames are not necessary reliable to prove a genetic inheritance.  Peoples' names change and those who don't have accurate histories of their families through the centuries may not know who among those living today are in fact descendants of their patrilineage.  The prosecutor did not ask Harmon how many people today are descendants in the tree of Dyleski's patrilineage.

In the case of someone like Prince Charles of England, patrilineage could be charted with great accuracy for centuries because his royal family is the subject of historians and records.  Many, but probably not all of his patrilineal ancestors could be determined and their progeny today identified.  In the case of Scott Dyleski that is probably not so. So there is no statistical reference point for the 3-10 sample.

All that can be said based upon the fact the YSTR profile of male genetic material is in the blood on Pamela Vitale's foot.  That, in turn, matches the YSTR profile of Dyleski so he cannot be excluded as being the donor of the sample.  In addition, and this is an important addition, scientific expertise cannot exclude all patrilineal related male relatives and an unknown number of unrelated males as being the donor of the sample.  Unrelated males are a possibility that cannot be excluded because two identical Y-STR haplotypes can be identical due to random mutation.

How will the jury evaluate the Yfiler testing of Y-STR in the Dyleski case?

The use of Y-STR in criminal cases is so new that the defense's legal motion to exclude it use at trial remains before Judge Barbara Zuniga.

On February 17, 2005, the Orange County Register reported that 7-year-old Samantha Runnion's kidnap-murder trial marked the first time in California that Y-STR analyzed male-specific genetic evidence was allowed in a criminal trial:

It is the first time that such Y-STR or male-specific DNA, has been allowed in a criminal trial in California, and one of the first times it has been approved for a criminal trial in the United States. Prosecutors believe that the DNA material found under a fingernail on Samantha's left hand links Alejandro Avila, 29, to the July 15, 2002, kidnapping and murder. Superior Court Judge William Froeberg allowed the evidence after a five-week pre-trial hearing after Deputy District Attorney Camille Hill presented evidence that Y-STR profiling is accepted as valid by the scientific community....

Orange County Deputy District Attorney Susan Schroeder said the DNA evidence approved this morning by Froeberg are pieces of a large puzzle that connect Avila to the crime. Prosecutors say they also have circumstantial evidence, a partial identification and more traditional DNA evidence linking Avila to the kidnap and murder.

On February 17, 2006, prosecutor Hal Jewitt called David C. Stockwell to the stand to explicate and tie up loose ends regarding the Y-STR test and to show other DNA evidence to tie sample 3-10 to Dyleski.

Stockwell is the senior criminalist in the Contra Costa County Sheriff's lab in Martinez and was quickly found qualified by the judge as an expert criminalist with a specialty in DNA analysis.  He testified that when he first obtained the blood swab from Vitale's right foot, which was labeled 3-10, he scanned it for foreign DNA, and compared what he could find to a profile of a Mr. Wheeler, who initially was the only reference sample provided to him.  However, Wheeler, a neighbor who had argued with Horowitz and his wife, and who was initially a suspect in the Vitale murder, but then conclusively ruled out, was not the source of the DNA.

Stockwell then obtained the oral swab from Dyleski, labeled 12-1.  Stockwell tested sample 3-10 for 13 markers, but he could not obtain a full profile. Of 4 markers in sample 3-10, he found Dyleski could be a contributor. There was nothing to exclude him.  But could Dyleski be included as a minor contributor in sample 3-10? At loci 13 in sample 3-10, Stockwell found 10 distinct genetic markers which were foreign to Pamela Vitale's sample.  However, Dyleski shared all 10 of these markers.  Therefore, Stockwell opined that the statistical probability of Dyleski being a contributor to sample 3-10 was:

1 in 81,000 Africans

1 in 43,000 Caucasians

1 in 23,000 Hispanics

But Stockwell hedged about the results. He testified that there was masking - the amount of DNA from Pamela was great and that of any foreign minor contributors was small.  In sample 3-10 there was not a marker at all 13 sites.  Therefore, Stockwell pined that he could only make an assumption that Dyleski was the one and only minor contributor to sample 3-10.  He recommended that a portion of the sample 3-10 DNA be independently tested.  Accordingly he sent sample 3-10 to the Serological Research Institute for Yfiler testing of the Y chromosome only. Stockwell did not test the foreign material in 3-10 to determine its nature - blood, saliva or epithelial because the amount of material was so small.  Finally, he testified he could not submit the profile of the foreign material in 3-10 to the FBI codex because, as his Note on page 36 stated, "Samples entered into Codex = none. Insufficient profile."  The FBI Codex is the combined DNA index system for local state and federal law enforcement.  Therefore, Stockwell developed the statistic "1 in 43,000" Caucasians in regard to Dyleski's DNA being a contributor to the blood on Vitale's right foot, based on an "insufficient profile."

Stockwell testified that 45 items were tested for DNA in the Dyleski case. DA Jewitt led Stockwell through the rest of his DNA forensic investigation.

First, the knife.

During the preliminary hearing Esther Fielding, mother of Scott Dyleski, testified that Dyleski's girlfriend gave her his folding knife after her was arrested and she separated it out from some of his other belongings when she and her mother met at the house of Esther's sister in Bolinas. Esther burned some belongings, put others into a storage area on the Bolinas property, and then put the knife into a suitcase in her car. Ultimately her lawyer gave it to Contra Costa County law enforcement.  A powerful connection in the eyes of the jury is to connect the victim's DNA to the weapon proven to be used to commit the crime, especially if the suspect's DNA is also on the weapon. Stockwell testified that Vitale's DNA was not found on the knife.

How about DNA in the trailer where Pamela was murdered?

DA Jewitt did not introduce any evidence of Dyleski's DNA being found at the crime scene, the trailer home, where the murder occurred, other than the blood sample 3-10 from Vitale's foot?

The DA presented a picture of the suspect being covered up at the scene by a long trench coat, a ski mask, and gloves.  However, the fact no other DNA from Dyleski was found at the scene seems highly unusual given that the suspect allegedly drank a glass of water and took a shower at the scene.

Then DA Jewitt focused on the duffle bag and its contents.

Esther Dyleski testified that she had made arrangements to have an old van she had abandoned removed from the Curiel's property where she and Scott lived a week before Vitale's murder.  On Monday, two days after the murder, Esther Dyleski and Joe Lynch were clearing brush on the property to meet a deadline imposed by local fire department to clear it away.  In the course of this work, she decided to make sure there was nothing of value in the van.  She, a short woman, opened a front door and peered into the back of the van.  She testified she saw a black tote canvas bag in the backseat of the van.  She reached inside it and pulled out a long black rain coat.  She testified she didn't see anything else in the bag.  She later asked Scott if the bag was his, and she testified, "He said something about old clothes." DA Jewitt then asked Esther if, in fact, she had told a deputy sheriff that Scott said, "It was old anyway and I just left it up there."  Esther denied saying this and said everything she said should be on video tape and it all was videotaped and she had told the deputy she wanted it videotaped. DA Jewitt didn't produce the video tape. Instead, he went ballistic.  He moved the court that Esther be declared a "hostile witness".

The judge denied the motion.  Esther wouldn't budge.  She would not say that the duffel bag belonged to Scott or that she saw any of the contents other than the long coat.  She would not say that Scott said the duffel bag or any of its contents were his.

Jewitt plowed on to other matters regarding the duffel bag.  Prior to Esther's testimony Jewitt had shown through the testimony of Fred Curiel that members of the household shared bags and clothing at times.  However, Fred Curiel would not identify the duffel bag or its contents as definitively belonging to Dyleski.  Apparently the bag has a name label on it stating "Scott Dyleski".

Members of law enforcement had testified earlier that they obtained the duffel bag and its contents during a search of the property sometime after Esther and Joe Lynch had seen it in the van on Monday.

DA Jewitt then questioned Senior Criminalist Stockwell about many of the 45 items which were tested for DNA.  Some of these were allegedly obtained from the duffel bag, and there was the blood swab from the foot, and a sample(s) from a knife obtained from Esther Dyleski's lawyer.  There may be other items among these 45 which the DA did not bring up at the preliminary hearing.

The DA carefully questioned Stockwell about the items contained in the duffel bag which law enforcement retrieved from the back of the van.

Stockwell testified that tests showed blood stains on some items contained in the duffel bag: one ski mask, one long sleeve shirt and one right hand glove. Blood stains were on the duffel bag itself.  Only the black rain coat contained no blood stains.

First, Stockwell explained the DNA tests on the duffel bag.  Two samples were obtained from the external area of the bag. Sample 13-9-1 contained a mix of a major contribution of Vitale's blood and a minor contribution.  Statistics that the blood in the sample was Vitale's were:

1 in 62 quadrillion Africans (A quadrillion is 1 million multiplied by 1 billion)

1 in 13 quadrillion Caucasians

1 in 14 quadrillion Hispanics

Dyleski could have been the minor contributor of genetic material in sample 13. 7 loci matched.  The statistics were:

1 in 450,000 Africans

1 in 560,000 Caucasians

1 in 65,000 Hispanics

DA Jewitt through his expert Stockwell illustrated a big breakthrough in the case.  Pamela Vitale's blood was definitely on the duffel bag.  Now it was clear why Jewitt was so intent on making a record that the bag was placed there by Dyleski, a point which his mother refused to acknowledge in her testimony.  Despite her testimony Jewitt indicated a sheriff had obtained a statement from her to the contrary.

Regarding Sample 13-9-2 from the exterior of the duffel bag, Stockwell testified that Vitale was the major contributor of genetic material. However there was an additional genetic marker that neither Vitale nor Dyleski had.  Stockwell opined that a genetic contribution came from someone other than Dyleski. For the first time, in the preliminary hearing, there was evidence of a third party involved in some instrumentality of the crime.

Esther Fielding testified that she pulled the black rain coat out of the duffel bag.  She did not testify that she had ever handle the duffel bag.

Obviously, the DA could try to match the new third party sample to someone such as Esther or other inhabitants of the Curiel household, but it appears he has not.  At the conclusion of the preliminary hearing the question of the third party DNA remained.

Next Stockwell testified that he obtained two stains from the exterior of the glove found in the duffel bag and two stains from the interior of the glove.  Blood had saturated through the fabric.  The two exterior stains and one interior stain contained Pamela's genetic material.  The fourth swab of the inside of the glove was a mixed sample.  The major genetic contributor was Vitale, and there was a two alleles which indicated there was genetic material which was neither Dyleski's nor Vitale's.  A third person had contributed to the stain on the interior of the glove. Again, the question was raised?  Who wore or touched that glove other than Dyleski?  Is law enforcement going to attempt to match that DNA to any other source?

DA Jewitt then focused Stockwell on the ski mask found in the duffel bag.

Six areas of the ski mask were tested. Four of these areas were blood stains.  Two were "background" meaning that no stain was apparent but that they were areas where the wearer might contribute DNA.

All four of the blood stains matched Pamela Vitale only.  Statistics that the blood in the sample was Vitale's were:

1 in 62 quadrillion Africans (A quadrillion is 1 million multiplied by 1 billion)

1 in 13 quadrillion Caucasians

1 in 14 quadrillion Hispanics

Around the opening for the mouth area, there was single source of DNA - Dyleski.  The statistics were:

1 in 1.8 quadrillion Africans

1 in 780 trillion Caucasians

1 in 1.6 quadrillion Hispanics

Regarding the background area around the eye opening of the sky mask, there was a mixture of the DNA containing three additional alleles that were not those of Vitale or Dyleski.  Thus, the DNA of at least one and possibly three individuals who were not Scott Dyleski or Pamela Vitale was found at the opening.

At this point in the Stockwell's testimony, it appeared that one other person besides Dyleski had worn or touched the inside of the glove and that at least one and maybe three persons other than Dyleski had worn or touched the ski mask around the eye opening of the mask.  Jewitt and Stockwell did not indicate any further attempts to match these unknown genetic profiles had occurred.

Next, Stockwell testified that the long sleeve shirt found in the duffel bag was tested in five areas.  Four of these areas contained blood and One1 was "background".  Of these areas, only one of them, a blood stain in the center of the chest area of the shirt could be typed.  The genetic material was from Dyleski only. The statistics were:

1 in 1.8 quadrillion Africans

1 in 780 trillion Caucasians

1 in 1.6 quadrillion Hispanics

There was no DNA from Vitale on the shirt.

Stockwell testified that no samples could be obtained from the long black rain coat.

Finally, Stockwell testified that the shoes in the duffel bag had four stains. Three of these provided results. Two stains showed Vitale was the contributor. One stain from the sole of the shoe showed three potential contributors, Vitale, Dyleski, and a third person. Regarding Dyleski's contribution there was a limited profile -- nine out of thirteen markers.  The statistics were:

1 in 13 Africans

1 in 6 Caucasians

1 in 9 Hispanics

Will DA Jewitt be able to convince a jury that DNA evidence links Dyleski to the murder of Pamela Vitale?  The use of the Yfiler to attempt to link Dyleski to the blood found on the victim's foot and the use of PCSR on a sample insufficient to feed into the FBI codex will be hotly disputed, especially since Yfiler is a new scientific technique.  The California Supreme Court has yet to rule on the Avila case where Yfiler was accepted as evidence passing the Kelly-Frye test.

So what did DA Jewitt prove so far? He proved probable cause that Dyleski was involved with the duffle bag and the ski mask and shoes which contained Vitale's blood stains and his genetic material.  Whether he used them during the time he allegedly killed Vitale is another issue which must be proven.

Will theories of "planting" and "staging" and DNA contamination be used to rebut the issue?  Damning to Dyleski is the fact that the DNA from the background sample taken around the mouth opening of the ski mask matches his.  However, the genetic material around the eye opening is that of at least one other person and not Dyleski.  DA Jewitt may have proved Dyleski cannot be excluded as a male Y chromosome contributor to a blood stain on Vitale's right foot.  The mask and shoes also contained genetic material of at least one other person regarding each item.

Helpful to Dyleski's defense is the fact that glove stained with Vitale's blood cannot be linked to his DNA.  One stain on the inside of the glove was linked to a person other than Vitale and Dyleski.  There is no proof Dyleski wore or touched the glove.  Someone else did. It can be shown Dyleski wore the long sleeve shirt and it had one blood stain.  But no stains linked to Vitale were found on the shirt.  How could he have won that shirt and engaged in a brutal bloody killing without Vitale's blood being on it?

The long black rain coat showed no DNA stains from Vitale or Dyleski.  The knife does not contain any blood stains linked to Vitale.

The gag order in the Dyleski case prohibits witnesses from talking about the case.  This results in an attempt to keep all leads under the control of law enforcement and the DA.

However, after this preliminary hearing the issue of third party culpability is loud and clear.  Is law enforcement seeking accomplices?  Did 16-year-old Dyleski, 5'6" tall and slender, with no history of violence, commit this brutal crime and moreover did he commit it alone?  What was the motive? How did a credit card fraud scheme to grow pot ratchet up to murder in the first degree?  Did a third party dominate Dyleski, orchestrate his conduct, exploit some mental problem of Dyleski or actually commit the crime?  The prosecutor does not have to follow up on these DNA leads to third parties.  But the issue will be raised at trial. The jury will wonder.  The public might not forget it. What if another crime with a similar modus operandi occurs in the area?

In People v. Hall (1986) 41 C3d 826, the California Supreme Court set standards when a defendant wants to prove third party culpability to a jury. The Court held:

To be admissible, the third-party evidence need not show "substantial proof of a probability" that the third person committed the act; it need only be capable of raising a reasonable doubt of defendant's guilt. At the same time, we do not require that any evidence, however remote, must be admitted to show a third party's possible culpability. As this court observed in Mendez, evidence of mere motive or opportunity to commit the crime in another person, without more, will not suffice to raise a reasonable doubt about a defendant's guilt: there must be direct or circumstantial evidence linking the third person to the actual perpetration of the crime....

Courts should simply treat third-party culpability evidence like any other evidence: if relevant it is admissible (§ 350) unless its probative value is substantially outweighed by the risk of undue delay, prejudice, or confusion (§ 352). We recognize that an inquiry into the admissibility of such evidence and the balancing required under section 352 will always turn on the facts of the case. Yet courts must weigh those facts carefully....

Furthermore, courts must focus on the actual degree of risk that the admission of relevant evidence may result in undue delay, prejudice, or confusion.

Dyleski's defense at trial may well be there is reasonable doubt of third party culpability, and that the duffel bag was a plant.

However, no matter what Dyleski's defense is, the public is owed some clarification about third party culpability in the DNA testing.  If not, irrespective of whether Dyleski is or is not guilty, one must infer from the evidence produced at the preliminary hearing that at least one other brutal murderer of Pamela Vitale may be running loose.  The DA cannot cherry pick his DNA results.  The judge is certainly too smart for that. And most jurors know a bamboozle when they see it.

Kathryn Joanne Dixon © July 17, 2006

PDF FILES RE: DEFENDANT'S MOTION RE: DNA ADMISSIBILITY.  As of July 26, 2006, final arguments re: DNA motion have yet to be heard.

Motion For Hearing Regarding Admissibility Of DNA Evidence

People's Response To Defendant's Motion For Kelly Hearing Re: Y-STR

Reply to Prosecution Opposition to Motion for Hearing Regarding Admissibility of DNA Evidence

People's Sur-Reply Re: Defendant's Motion For Kelly Hearing Re: Y-STR