LAS VEGAS — A pair of DNA experts told jurors in the so-called Black Widow murder trial that red stains from Margaret Rudin's bedroom have the same genetic profile as blood from a handkerchief allegedly belonging to her slain husband.

Connecting the red dots to the handkerchief is crucial for the prosecution to prove the 57-year-old socialite killed her fifth husband, Ron, in the couple's bedroom. Authorities have no direct DNA samples from the murdered real estate developer, but they do have the cloth witnesses say Rudin used when he had nosebleeds or cut himself shaving.

His charred remains were recovered in a desert fire pit in 1995. Prosecutors contend his wife, eager to inherit her share of his $11 million fortune, shot him at least four times as he slept and then had his body dismembered and torched near Lake Mohave.

Rudin, whose trial is now entering its second month, claims she had nothing to do with her husband's December 1994 disappearance and has pointed the finger at his shady business associates.

The experts from two private laboratories — Cellmark Diagnostics and Lab Corp — testified Monday that the stains found on the bedroom's walls, ceiling and box spring as well as the handkerchief, found in a bathroom drawer, were consistent with coming from a single source.

The newest member of Rudin's defense team, prominent attorney John Momot, tried to undermine the expert testimony, getting both scientists to acknowledge that "consistent does not mean absolute."

But Lab Corp's Megan Clement showed jurors statistics that the genetic profile was shared by only one in 702 million Caucasians.

Clement also testified that she did more extensive tests which indicated that three of the four samples were male DNA. Gender testing of the fourth, the box spring, was inconclusive. The gender of the DNA in the stains is important because Ron Rudin's former wife, Peggy, committed suicide with a gun in the same bedroom in 1978. Brain matter found on the ceiling of the bedroom during the investigation into Ron Rudin's death was later traced to the suicide.

Cellmark biologist Richard Ballmann said spots found on a "glamour shot" of Margaret Rudin which hung above her bed at the time of the alleged shooting contained human DNA but further genetic typing was unsuccessful.

Also Monday, the jury heard about the discovery of the murder weapon, more than a year after Ron Rudin's disappearance. A scuba instructor recalled finding a .22-calibre gun while diving off an island in Lake Meade in July 1996. A police ballistics expert testified the semiautomatic weapon fired the bullets that killed Rudin, and an ATF agent displayed records showing Ron Rudin told inspectors a .22-calibre gun was stolen from him in 1988. Prosecutors maintain his wife is the only one who had access to this weapon.