Kelly Test Requirements and Dog Scent Trailing Evidence                         

Foundational Requirements for Dog Scent Trailing Evidence

(1) Dog scent trail evidence is admissible without the need to meet the foundational and reliability requirements as described in People v. Kelly (i.e., the “Kelly/Frye test”).  (2) Dog scent trailing evidence is admissible so long as a proper foundation is laid concerning the dog handler’s expertise, the present ability of the dog in issue to trail a human, and some corroboration that the person being trailed had in fact been at the location in issue. 

Defendant Scott Lee Peterson lived with his wife, Laci, in Modesto, California.  Laci worked as a substitute teacher while defendant ran a startup fertilizer company out of a leased warehouse.  After a few years in Modesto, Laci became pregnant with their first child who they named “Conner,” with a due-date in February, 2003.  On the day before Christmas, 2002, neighbors found the Petersons’ dog with his leash attached wandering around the neighborhood.  With neither defendant nor Laci home, the neighbors merely put the dog in the Petersons’ backyard.  Defendant came home at about 4:30 p.m. that afternoon, washed his clothes, and ate some pizza.  He then called Laci’s mother to see if she had seen Laci that day, referring to his wife as “missing.”  With the police eventually being called, it was determined that there were no signs of forced entry at the Peterson house and Laci’s purse was still there.  Defendant suggested that maybe she had been accosted while walking the dog.  He also claimed that he had gone fishing that day in San Francisco Bay despite the cool, drizzly weather.  Defendant, however, was immediately a suspect, giving non-committal and inconsistent answers to questions.  He also showed little concern that Laci was missing. When asked, defendant claimed that there were no current problems in his marriage and denied that he was involved in any love affairs with anyone.  Skipping a whole bunch of othere little pieces of evidence here and there, all indicating that defendant might have had something to do with his wife’s disappearance, the kicker came when on December 30th (six days after Laci’s disappearance), a woman named Amber Frey reported to the Modesto Police that she was in the midst of an affair with defendant, and had been since November (Can we spell, “motive ”), and that they had in fact been sexually intimate.  Frey soon figured out that defendant had been telling her a whole pack of lies since they met, including that he had never been married, soon changing that story to having been married, but that he lost his wife and was facing the prospect of spending the holidays without her for the first time.  Meanwhile, the Modesto Police collected articles from the Peterson home what Laci would have touched (a slipper and a pair of her sunglasses), intending to eventually use them with “trailing dogs” so that they could search for Laci’s scent.  Under authority of a warrant, police placed a surveillance camera outside the Peterson home and GPS tracking devices on his vehicles, including a series of vehicles defendant rented for a few days at a time.  The surveillance camera didn’t help much, but the tracking devices showed that defendant drove the approximately 90 miles from his home to the Berkeley Marina in San Francisco Bay at least five times in January, each time using a different vehicle.  Defendant also started making a lot of big changes, such as terminating the lease he had for the warehouse where his business had been, making preparations to sell his house, trading in Laci’s car for a pickup truck, stopping mail delivery and opening a post office box, converting Conner’s room into a storage space, and cancelling the satellite television service to his home, explaining to them that he was moving overseas.  Finally, in April, both Laci’s and Conner’s badly decomposed bodies washed ashore after a storm hit the San Francisco Bay area.  Although the cause of their respective deaths could not be determined, an autopsy indicated that Laci was still pregnant with Conner when she died.  Around that same time, defendant did things indicating that he was about to flee (e.g., bought a car with cash in his mother’s name while using a fake driver’s license number, growing a goatee and mustache, dying his hair, and not returning phone calls).  He was therefore arrested on April 18th and booked on two counts of murder.   When arrested, defendant was in possession of nearly $15,000 in cash, foreign currency, two drivers’ licenses (his own and his brother’s), a family member’s credit card, camping gear, considerable extra clothing, and multiple cell phones.  At trial, the prosecution’s theory was that defendant had killed Laci sometime on the night of December 23-24. Then, on the morning of the 24th, he let their dog out with his leash on to make it appear something had happened while Laci was walking him. He took her body to the Berkeley Marina in his boat which he stored at his leased warehouse, motored out to an area near Brooks Island, and slipped her body—attached to homemade concrete weights he had fashioned as an anchor—into the bay.  He then returned to Modesto, dropped the boat off at the warehouse, put gas on a tarp he kept in the boat to cover any odors left from Laci’s body, washed his clothes, and proceeded with the ruse that Laci was missing, all the while hoping her body would never be found.  The jury convicted defendant of murder in the first degree for killing Laci and murder in the second degree for killing Conner. (P.C. § 189.) It also found true a multiple murder special circumstance.  (P.C. § 190.2(a)(3).)  Sentenced to death, his appeal to the California Supreme Court was automatic.

The California Supreme Court reversed the death penalty finding, citing errors in the selection of a death qualified jury, but unanimously confirmed his conviction (but see Note, below).  Among the issues on appeal (other than the defective jury selection process) was the admissibility of dog scent trailing evidence.  Using Laci’s slippers and dark glasses seized earlier from the Peterson home, various dog handlers used their dogs to trail Laci’s scent from her home in Modesto, in and around Peterson’s Modesto warehouse, on highways leaving Modesto, and at the Berkeley Marina in San Francisco Bay.  After listening to extensive testimony from, and cross-examination of, the various dog handlers concerning their training, as well as their dogs’ training and past performance, the trial court excluded all the dog scent evidence except for what occurred at the Berkeley Marina.  The reason for excluding all the other dog scent evidence was the lack of sufficient corroboration that Laci had actually been where the dogs purported to trail her scent. The Berkeley Marina evidence differed because there was corroborating evidence that Laci had been present in the area; i.e., with Laci’s remains washing ashore very near the Marina.  The evidence that was admitted consisted of testimony from a dog handler (Eloise Anderson) who was a member of the Contra Costa County Sheriff’s Department search and rescue team.  Anderson testified at trial about scent trailing she conducted at the Berkeley Marina with her dog “Trimble” on December 28th, 2002 (four days after Laci’s disappearance).  Using Laci’s sunglasses obtained from the Petersons’ home, and while wearing rubber gloves to conceal her own scent, Anderson presented the sunglasses to Trimble while giving a trailing command.  At one of the two Berkeley Marina access points, Trimble responded with a “no scent trail” signal. In the second location, however, Trimble “lined out,” i.e., pulled her harness line taut with a level head.  Trimble led Anderson from an area near the parking lot entrance down to one of the marina piers and to a pylon on the pier where a boat could have been tied, giving Anderson an “end of trail” signal at that point.  Evidence of Trimble’s hit on Laci’s scent at this location was of course important to show that Laci (or her body) had in fact been at the Berkeley Marina and not at home walking her dog as defendant had claimed. Defendant argued that admission of this evidence was error because the trial court had failed to require a hearing pursuant to People v. Kelly (1976) 17 Cal.3rd 24.  Defendant also argued that the prosecution had failed to establish the legally required evidentiary foundation necessary before such evidence can be admitted.  The Court of Appeal disagreed as to both arguments. 

(1)  Kelly Test:  Pursuant to People v. Kelly, when the admission into evidence of an expert’s testimony is the issue, and that testimony relates to the use of novel scientific methods or techniques, the proponent of that evidence must first demonstrate the technique’s reliability through testimony from an expert qualified to offer an opinion on the subject. The technique's reliability, in turn, depends upon a showing that it has achieved general acceptance among practitioners in the relevant field.  Finally, the proponent of the evidence must show any procedures necessary to ensure the technique's validity were properly followed in the case at issue. The purpose of these threshold requirements—commonly referred to as the “Kelly test”—is to protect against the risk of credulous juries attributing to evidence cloaked in scientific terminology an aura of infallibility.  (The Feds follow a similar requirement pursuant to Frye v. United States (D.C. Cir. 1923) 293 F. 1013, thus establishing what is more popularly known as the “Kelly/Frye test.”) However, not every issue requiring expert testimony needs to satisfy the Kelly test.  People v. Kelly does not apply unless the technique at issue is “novel;” i.e., “which is new to science and, even more so, the law.” Also, Kelly only applies when the technique at issue is one whose reliability would be difficult for laypersons (i.e., the jurors) to evaluate.  “(N)o Kelly hearing is needed when ‘[j]urors are capable of understanding and evaluating’ the reliability of expert testimony based in whole or in part on the novel technique.”  (People v. Jackson (2016) 1 Cal.5th 269, 317.)  Prior case law has already held that the Kelly test does not apply to dog scent evidence.  (See People v. Craig (1978) 86 Cal.App.3rd 905.)  So long as the proper evidentiary foundation—i.e., “the present ability of a particular well-trained dog to trail a human”—is established, then the evidence is admissible without the need for a Kelly hearing.  Juries are perfectly capable of understanding such evidence. 

(2)  Evidentiary Foundational Requirements:  As for the evidentiary foundation necessary before dog scene evidence is admissible at trial, the California Supreme Court has required that the proponent of the evidence establish as background qualifications the adequacy of the handler’s and the dog’s training, and supply evidence of the dog’s reliability in trailing humans. (People v. Jackson, supra, at pp. 321–322.) The proponent of such evidence must also show the adequacy of the manner in which the dog was given a scent to trail—whether by being allowed to sniff the beginning of a known trail or by being “presented with a scent article”— and then asked to smell for a corresponding trail of the same scent.  Also, there must be some independent evidence tending to confirm that the person found at the end of the trail was indeed the person who left the scent trail and supplied the initial scent.  The Court ruled that the People had met it evidentiary foundational requirements as described above. Anderson’s testimony was sufficient to show that Trimble had the necessary qualifications as a scent tracking dog.  Anderson’s testimony also established her own training and experience in this field.  Most importantly, the necessary foundational requirement that there be corroborating evidence that Laci had in fact been in the Berkeley Marina area (i.e., her body washing up on shore nearby and in the direction the local tides, per expert testimony, would have taken her) had been established.  Also, contrary to defendant’s assertions, there was evidence that Trimble had the training and ability to pick up the scent of someone enclosed in, for instance, a tarp and carried in a boat; referred to as an “enclosed target.”  Based upon the above (and a few other more frivolous arguments similarly rejected by the Court), it was held that the dog scent evidence was properly admitted.

I briefed this case primarily because there’s not a lot out there on dog scent evidence.  I found this case very instructional (even if, as written, a bit disjointed and hard to follow) on the issue.  Prosecutors really need to read the whole decision if you have a case involving dog scent evidence because there’s more to this issue that limited time and space prevents me from covering here in any detail.  For instance, a modified version of CALJIC No. 2.16, which provides guidance concerning how to evaluate the dog-trailing evidence, was approved.  And other cases are discussed involving different types of dog-sniffing evidence with different foundational requirements, such as where the dog is exposed to a scent and then watched to see if it shows an interest in various locales frequented by the defendant.  (People v. Willis (2004) 115 Cal.App.4th 379.)  Also, another variation is discussed where a dog is given pads with scent from shell casings and the victim’s shirt, after which a lineup of pads with scents from various people, including the defendant, is presented to the dog.  (People v. Mitchell (2003) 110 Cal.App.4th 772.)  So why was the penalty verdict reversed, you might ask   That’s because the trial court erroneously dismissed a bunch of prospective jurors based solely on the jurors’ responses in written questionnaires expressing opposition to the death penalty, even though the jurors gave no indication that their views would prevent them from following the law in the appropriate case.  It’s a hard and fast rule (that the prosecutors here should have known) that merely expressing some opposition to the death penalty as a general matter is not legal grounds by itself to dismiss a juror.  (See Witherspoon v. Illinois (1968) 391 U.S. 510.)  So the case is being returned to allow for a new penalty phase trial should the prosecution so decide to go forward with it.  Also, since this decision was reported, I’ve learned via news reports that the Supreme Court has also determined that the whole case (not just the penalty phase) has to be returned to the trial court in that it has belatedly come to light that one juror failed to disclose in voir dire that she had at one time feared for her own unborn child when she was being harassed by the ex-girlfriend of her boyfriend, necessitating her getting a restraining order; sometime surely the trial attorneys should have been made aware of while selecting the jury.  So the Court is now sending the entire case back to the San Mateo County Superior Court to hold an evidentiary hearing for the purpose of deciding whether Peterson should be granted a new trial on the grounds that “Juror No. 7 committed prejudicial misconduct by not disclosing her prior involvement with other legal proceedings, including but not limited to being the victim of a crime.”  So stand by on that issue.