Poorly Conducted Trailing and Scent Identification Procedures Lead to Wrongful Accusation

In a case arising in Texas in 2006, police, largely on the basis of evidence provided by a dog handler named Keith Pikett, concluded that Michael Buchanek had murdered Sally Blackwell. Several months after the investigation began another individual, Jeffrey Grimsinger, confessed to having killed Blackwell. Had it not been for this confession, the canine evidence provided by Pikett might have put Buchanek, who did a tour training Iraqi police, in prison. Grimsinger was suggested as a suspect early in the investigation but this seems to have been ignored by the officer in charge of the case, Sam Eyre.

Blackwell was abducted from her home on March 13. Her body was found two days later on March 15, 2006. Before the body was found, dogs and handlers from the Texas Department of Criminal Justice (TDCJ) had been brought to help search the area where Blackwell’s cell phone and purse were found. The dogs picked up no trail at the location and the handlers believed that the phone and purse had been thrown from a car. (The Texas Department of Criminal Justice has 47 kennels throughout its system, with 101 kennel staff (as of 2006). About half the kennels hold tracking dogs used primarily to track escaped convicts, but also to help law enforcement. There are also scent-specific canines that include drug detection dogs in the TDCJ system.)

The Police Department of Victoria, Texas, employed Keith Pikett, a handler of trailing and scent identification dogs, to help in the investigation. An affidavit sworn to by Eyre stated that Pikett’s dogs trailed from the place where Blackwell’s body was found to Buchanek’s home. This was false, as other evidence established that the dogs trailed to the home of the victim, and only after reaching Blackwell’s house was Pikett told that a “person of interest” lived at a different location. The dogs were then taken to a street near that location and re-scented, after which they went to Buchanek’s home. The dogs would have passed this house when they were trailing from Blackwell’s body to her home, but if they did so they did not alert at the time.

There was another problem with the tracking in that the investigators believed that Blackwell’s body had been taken to the place where it was found in a vehicle. Thus, trailing from the location where the body was found to either house would have involved dog’s following a body in a car. Pikett argued that this was in fact possible, but the TDCJ handlers doubted it could be done. Some of those handlers, according to Buchanek’s complaint, expressed the belief that Pikett was “full of b.s.” The federal district court observed that the route followed by the dogs from the location of the body to the victim’s home would have required trailing the car transporting the body over five miles.

Pikett cited a piece in the FBI’s Forensic Science Communications noting that ventilation systems in cars move fresh air through the interior of a vehicle and into the external atmosphere, conceivably laying a scent trail a dog could follow. (Stockham, R.A., Slavin, D.L., and Kift, W. Specialized Use of Human Scent in Criminal Investigations. Forensic Science Communications, July 2004, vol. 6(3)). Research might support this possibility for short distances, but the five miles involved in this case and several major highways would truly be exceptional.

When Pikett and his dogs arrived in the vicinity of Buchanek’s home (after the dogs supposedly trailed to Blackwell’s home), an officer asked a man walking his dogs to remove them from the street because police dogs were coming. The court said this may have indicated that Pikett expected his dogs to trail to Buchanek’s house. The court also noted that the officer was preceding the dogs and it may have been his scent they were following. Even worse, it may have meant that Pikett was leading his dogs, rather than the other way around.

Pikett also conducted a scent lineup. The scent for Buchanek used in the lineup appears to have been a legal document Buchanek may not have touched for two years and may have been more recently handled by law enforcement officers. The other scents in the lineup may have come from “filler scents” that Pikett kept for such purposes, though this was not definitely established. (Another case involving Pikett’s services describes Pikett testifying that he has “a large selection of scent samples” for scent lineups, and that he has separated his samples by race and gender. Winfrey v. State, 2009 WL 1636849 (2009).) If filler samples were used here, the scents were not prepared in the same way or at the same time, which would be a serious defect in a scent lineup. There was also no evidence as to whether the dogs were on leads or not, or as to how Pikett was kept blind as to the placement of the suspect’s scent (if he was indeed blind). The lineup was performed in a police department parking lot. Officers who re-arranged the bags containing the scents in a row of cans may have touched the bags in this process, creating the possibility, if not the likelihood, of contamination. There were probably other problems with the scent lineup but there is no detailed description of how it was conducted.

In the two decisions of the federal district court, motions for summary judgment have been denied, clearing the way for a trial. Buchanek v. City of Victoria, 2009 WL 500564, 2010 WL 1268069 (S.D. Tex 2010). The case has received national attention when the first decision was released. John Schwartz, “Picked From a Lineup, on a Whiff of Evidence,” New York Times, November 11, 2009, p. 1.

Scent lineups have come to be called “junk science” by those who believe that wrongful convictions as a result of these lineups are all too common. This case may be unique in that a single handler may have turned trailing as well as scent identification into “junk science” in a single investigation. As I have argued before, and will again in a law review article, scent lineups can be conducted in a professional and precise manner, and the possibilities for error can be reduced to a level that makes them more accurate than visual eyewitness lineups often are and well within the range of certain forensic procedures commonly admitted as evidence in criminal prosecutions.

Addendum. Winfrey has been reversed by the Texas Court of Criminal Appeals. This court noted that no eyewitnesses put the defendant at the crime scene, the state was unable to match the defendant to a fingerprint and footprints found at the crime scene, and the defendant did not match the DNA profile obtained from the crime scene. The evidence convicting Winfrey consisted of his belief that he was the number one suspect when he wasn't and the fact he told a cellmate things he had heard about the crime but said nothing about his own involvement to the cellmate. The court found this "legally insufficient to support a conviction of murder beyond a reasonable doubt." The court cited other state courts that had held that dog-scent evidence was insufficient, standing alone, to support a conviction, and cited Taslitz (42 Hastings Law Journal 15 (1990)) in holding that scent-discrimination lineups were to be regarded as "separate and distinct from dog-scent tracking evidence." The court said that the scent lineup evidence could raise a "strong suspicion" of the defendant's guilt but could not convict him. A judgment of acquittal was entered by the appellate court. Winfrey v. Texas, 2010 WL 3656064 (Tex. Crim. App. 2010). Thanks to Gail Kikawa McConnell of the Fort Bend County, Texas, District Attorney's office for emailing me about the reversal.