A man executed in Oklahoma last year was placed at the murder scene by the testimony of now-disgraced police
chemist Joyce Gilchrist, but a police department memo says some of the scientific evidence she swore to does not exist.

The July 31 memo by a fellow lab scientist for the Oklahoma City Police Department refers to the case of
Malcolm Rent Johnson, who was executed on Jan. 6, 2000, after being convicted in 1982 of rape and murder.
Johnson, who had served time for two previous rapes, insisted he was innocent.

At Johnson's trial, Gilchrist testified that six samples taken from the victim's bedroom showed semen consistent
with his blood type. But a July 30 re-examination of those slides showed "spermatozoa is not present,"
says the memo signed by chemist Laura Schile.

Schile resigned Aug. 2 from the embattled forensics lab, citing a hostile work environment.  She names the lab's
three other scientists as agreeing that sperm is not present.  While the memo does not exonerate Johnson,
it marks the first time legal questions have been raised about Gilchrist's testimony in an execution case.

The memo also noted that Gilchrist's testimony had been criticized previously. Two appellate courts have ruled
Gilchrist gave false testimony about semen evidence in the 1992 rape and murder trial of Alfred Brian Mitchell,
whose death sentence was overturned earlier this month because of what one court called her "untrue" testimony.

"There are now two cases where the results stated in the (lab) report and testified to by Joyce Gilchrist contradict
independent expert re-examination of the actual physical evidence," Schile wrote.

Prosecutors said there was sufficient evidence separate from Gilchrist's testimony to convict Johnson.
But Oklahoma County Chief Public Defender Robert Ravitz, who represented Johnson at trial, disagrees.

"It really calls into question whether the state of Oklahoma executed an innocent person," he said Tuesday.

Problems with Gilchrist's testimony in other cases have led to the release of three inmates who served long
sentences, including one on death row. Based on a preliminary review, authorities previously said there was
no taint in the 11 cases where prisoners were put to death.

Gilchrist has previously denied any wrongdoing.

Ura Alma Thompson, 76, was found suffocated in her apartment on Oct. 27, 1981.
There were no witnesses to the crime, and no fingerprints matching Johnson's were found.

He was arrested after officers went to his home to question him about an unrelated parole violation and
noticed items belonging to the victim. A search led to the discovery of her apartment key in his nightstand.
He contended all the items were given to him by a third party.

Gilchrist told jurors that semen stains on the woman's bedspread and pillow case matched Johnson's blood type,
which constituted the bulk of evidence used to tie Johnson to rape. The only other evidence stained by semen
consistent with his blood type was a knee-high stocking, Gilchrist testified. That stocking has not been retested.
A vaginal swab contained sperm, but not enough to test, Gilchrist told jurors.

Gilchrist also testified that hair fragments matched Johnson's hair and that fibers matched a blue cotton shirt
he owned. Johnson's trial marked the first time she had testified about fiber analysis.

DNA analysis was not available at that time, and the court denied the defense's request for funds to hire its
own forensics expert. Johnson's attorney argued during trial that blue cotton shirts were so ubiquitous that the
fiber could not definitively be linked to Johnson.

Schile refused comment Tuesday on the memo contradicting Gilchrist's testimony, which she addressed to
Richard Smith of the Oklahoma City Municipal Counselor's Office.

Kyla Marshall, one of the chemists named by Schile, confirmed that when the slides purported to contain sperm
were retested, they revealed only a few fibers from the victim's bedspread and pillow case. Sperm does not
deteriorate for decades, she said.

Richard Wintory, a spokesman for the district attorney's office, said Tuesday that he still does not doubt Johnson's guilt.

"The evidence against Malcolm Rent Johnson is absolutely, uncontestably, overwhelming he done it, done it, done it,"
Wintory said. "This suggestion that an innocent guy was executed is not true about Malcolm Rent Johnson."

"I am confident he is guilty of murder," Oklahoma Attorney General Drew Edmondson said.

Gov. Frank Keating's office said he agreed the execution was appropriate.