The men in Purdie Guerra Clark's life keep turning up dead.

First her husband, Texas Instruments engineer Kim Alan Clark, was found shot to death in September 2006 in rural Collin County.

A month later, Robert Dwayne Murphy, who according to court records was the couple's live-in nanny and sexual partner, was found dead in a motel room in San Angelo, Texas, the victim of a heroin overdose.

Now Purdie Clark, 31, faces a murder charge in the poisoning death of James Phillips last month in San Angelo, according to a police report.

Clark was arrested Saturday after a car chase in Collin County and is being held in the county jail in lieu of $1 million bail. She is to be transferred back to West Texas in a couple of days, said Lt. Curtis Milbourn, a San Angelo police spokesman.

He said Phillips had been living with Clark but would not divulge why homicide investigators' suspicions turned to her.

Phillips, 60, was found "unconscious and not breathing" in their front yard Feb. 16. Authorities sent a sample of his blood to Tarrant County for testing, which revealed that he had been poisoned.

"There were some unusual things involved that led us to believe that Purdie Clark was, in fact, the one that had killed Mr. Phillips," Milbourn said.

Phillips is the third man to die in the past three years while in a relationship with Clark.

Kim Clark, 42, met her at a Dallas bar in the late 1990s and eloped in Las Vegas a few months later.

The couple was married for almost a decade and living in Princeton when the TI engineer was found dead near State Highway 205 in southeast Collin County. He had been shot twice in the head and left behind a guardrail about 20 feet from the road.

Murphy, the couple's live-in nanny, was immediately named as a suspect but was never arrested. He had moved in with the couple and their three children less than a week before Kim Clark was reported missing.

A Child Protective Services caseworker said the Clarks were swingers and that Murphy was their sexual partner, according to court documents.

About a month after Kim Clark's death, Murphy was found dead in a West Texas hotel room. An autopsy report said heroin byproducts were found in his system, and the death was ruled an overdose.

Purdie Clark's family said at the time that Murphy had sent her a letter in which he confessed to killing her husband. Although she has never been arrested or charged in Kim Clark's death, Collin County authorities say the case remains open.

"She is a suspect in her husband's murder," Lt. John Norton, a spokesman for the Collin County Sheriff's Department, said Monday.

CPS sent the Clarks' children – who were 5, 7 and 12 at the time – to live with their paternal grandparents in Kentucky.

On Friday, San Angelo police obtained an arrest warrant for Purdie Clark in Phillips' death.

The next day, authorities got a tip that she was in Collin County, and officers with the Department of Public Safety staked out a location.

Clark was there but she tried to run, authorities say. The officers arrested her after a car chase. In addition to the murder charge, she faces a count of evading arrest with a vehicle.

Milbourn, the San Angelo police spokesman, said investigators there are not ready to say there's any link between the deaths of the men in Clark's life.

"Nor are we prepared to say they're not connected," he said. "We're looking at every possibility."