A murder conviction involving dog scent evidence was overturned Wednesday after the Texas Court of Criminal Appeals unanimously held that such evidence may only serve a supporting role and must not be used by prosecutors as the main justification for a guilty verdict.

The court reversed the 2007 conviction of Richard Lynn Winfrey and ordered his acquittal, saying the evidence produced against him at trial was insufficient. The court claimed the alleged proof amounted to little more than vague tidbits of possible self-incrimination and a suspicion raised by dogs owned by a Fort Bend County sheriff's deputy that matched Winfrey's scent to articles of clothing worn by the victim.

Otherwise there was nothing to support the jury's verdict that Winfrey had killed high school janitor Murray Wayne Burr in his home in Coldspring in August 2004. Texas' highest criminal court did not reject evidence from so-called dog scent lineups per se. But it said the dog evidence played too great a role in the jury's decision in Winfrey's case.

San Jacinto County prosecutors had argued that two statements made by Winfrey were enough to support the conviction.

He had mentioned to a Texas Ranger investigating the murder that he assumed he was the top suspect. Winfrey also allegedly mentioned later to an inmate at the Montgomery County Jail that he had heard that a gun and knife collection were stolen from Murray's home after the murder.

The court ruled that those statements were not legally sufficient to establish guilt, with or without the dog scent evidence.

Scent lineup 3 years later

Forensic evidence from the scene did not implicate Winfrey.

A partial bloody fingerprint, a bloody shoeprint and a DNA profile worked up from the evidence did not match Winfrey, nor were any of the items stolen from Murray found in Winfrey's possession.

The dog scent evidence, produced from a scent lineup done almost three years after the killing, established an association of Winfrey's scent with articles of clothing worn by the victim, though the dogs' handler, Deputy Keith Pikett, was careful to testify that scent transfer did not have to occur at the time of the murder.

Attempts to reach Pikett for comment for this and previous stories on dog scent lineups and evidence were unsuccessful. A spokesperson for the Fort Bend County Sheriff's Department has repeatedly stated that Pikett has been asked not to comment to news media on the advice of attorneys for the department.

Derided as 'junk science'

Advocacy groups as well as other professional scent dog handlers have denounced Pikett and his dogs, which have proved useful in securing convictions in jurisdictions throughout the state over the last decade.

Last year the Innocence Project of Texas issued a scathing report on Pikett's work, calling it nothing more than "junk science." It cited cases in which Pikett's dogs found scent associations of suspects with crime scenes, only to have further investigation exonerate the suspect of any involvement. In some of those cases, the suspects were jailed and charged with the crime before being cleared.

The Court of Criminal Appeals, with one justice not participating, declared for the first time the significance of dog scent evidence at trial is limited.

"We conclude that scent-discrimination lineups, when used alone or as primary evidence, are legally insufficient to support a conviction," the court stated in its 16-page opinion. "To the extent that lower-court opinions suggest otherwise, we overrule them and expressly hold that when inculpatory evidence is obtained from a dog-scent lineup, its role in the courtroom is merely supportive."

Hailed as big step

Jeff Blackburn, chief counsel of the Innocence Project of Texas, hailed the ruling as a big step toward eliminating dog scent evidence from courtrooms, even if the court did not go that far.

"I think we've done a lot of damage — and this case does a lot more damage — to the use of this nonsense in Texas courts," Blackburn said. "I think this is a real opening. With the Court of Criminal Appeals, you have to measure progress in baby steps. Anyone looking to them for big changes in the criminal justice system is looking in the wrong place. But if you understand that, it's a real big step forward. At the very least, I think we have effectively put this guy out of business."

mike.tolson@chron.com