The Missouri Supreme Court overturned a man's death sentence Tuesday because his attorney failed to question the character of a murder victim who had child pornography on his computer.

The high court acknowledged in its unanimous ruling that character evidence about murder victims typically is barred. But when relatives of victim Ralph Lape Jr. testified about his generous character during the sentencing phase of Mark Gill's murder trial, defense attorneys should have countered by highlighting the smut on Lape's computer, the Supreme Court said.

Had Gill's attorneys done so, the Supreme Court said, jurors may have been less inclined to sentence him to death for the July 2002 kidnapping, robbery and shooting. The Supreme Court sent the case back to a lower court for a potential new sentencing hearing.

Gill was living in a camper trailer on Lape's rural Cape Girardeau County property at the time of the slaying, according to court records. When Lape took a Fourth of July weekend trip to a Kentucky lake, Gill remained behind and one of his friends, Justin Brown, found papers in Lape's home indicating he had a large amount of money in the bank.

Gill and Brown then plotted Lape's murder, kidnapped him when he arrived home and drove Lape to a rural area near Portageville where he was shot in the head and buried, according to court records. Gill and Brown each fingered the other as the triggerman during their separate trials. But Gill was sentenced to death and Brown to life in prison.

About a month before Gill's trial, prosecutors provided defense attorneys with a police report listing the file folders and directories found on Lape's computer, which Brown and Gill had used to transfer $55,000 from his bank account. The report included a list of instant message accounts with sexually explicit names.

The Supreme Court said that should have alerted Gill's defense attorneys to inquire about the computer's contents or interview the police officer who prepared the report. Because they did neither, defense attorneys were unaware that Lape's computer contained images of child pornography and bestiality and instant messages about sexual conversations.

"When the state introduced evidence of the victim's good character in the penalty phase, Gill's counsel should have rebutted the state's good character evidence with the sexually explicit contents of the victim's computer," the Supreme Court said in an opinion written by Judge Mary Russell.

Attorneys for Brown, whose trial occurred after Gill's, requested a copy of the victim's computer contents. Lape's relatives toned down their good-character references during the penalty phase of Brown's trial, so the computer pornography never was used as a rebuttal, the Supreme Court said.

If prosecutors go forward with a new sentencing hearing for Gill, he will be assigned different public defenders than those who originally handled his case, said attorney William Swift, who argued Gill's case on appeal.

Swift also had sought unsuccessfully to overturn Gill's conviction based on ineffective aid by his attorneys.

"We're happy that the court has ordered what it did. Obviously a new penalty phase is a good result for Mr. Gill," Swift said.

Cape Girardeau County prosecutor Morley Swingle was not immediately available Tuesday for comment, his office said.