Proving poisoning may test the DA

Clarification: A City & Region story on Wednesday said Kendra Thomas was a friend of James Keown, who is accused of murdering his wife by poisoning, and that she contacted the Globe to express shock at the accusations against him. Thomas was an acquaintance of Keown in high school. She had contacted the Globe to propose an unrelated story and subsequently expressed shock at the charges when interviewed.

It may be the weapon of choice for such mystery writers as Agatha Christie, but poison -- such as the antifreeze that prosecutors say a former Waltham man put in his wife's Gatorade to slowly kill her -- is an exceedingly rare path to murder.

From 2000 through 2004, only 63 of the nation's 70,140 reported murders involved poison, according to FBI statistics. The only recorded weapon used less often was explosives, which were involved in 29 slayings over the period. Firearms were used the most, in about 46,000 slayings.

''Homicides are crimes of passion and, obviously, poisoning isn't the most expedited fashion to carry out one's demise," said William Meade, general counsel for the Massachusetts District Attorneys Association and a former prosecutor who is not involved in the Waltham case.

But if the use of poison to murder someone is extraordinary, so too are the challenges facing Middlesex County prosecutors in the case of James Keown, according to legal specialists.

Middlesex District Attorney Martha Coakley said as much on Monday after she announced Keown had been arrested hours earlier during a break in the political talk show he hosted at a small radio station in his hometown of Jefferson City, Mo.

Keown, 31, is accused of poisoning his wife, Julie, with ethylene glycol, a substance found in antifreeze, over a five-month period until she died in September 2004 in what Coakley described as an effort to collect on a $250,000 life insurance policy. Julie Keown had repeatedly sought treatment for mysterious symptoms, including vomiting, nausea, and slurred speech, before she ended up in a coma in a hospital bed.

''I think it will be a complicated case," Coakley after the news conference. ''We've got a long period of time to cover. And in a lot of cases, we've got the gun, we've got the wound, we've got the knife. This will involve a lot of medical testimony."

As Julie Keown hovered near death at Newton-Wellesley Hospital in September last year, her kidneys failing, medical personnel determined that the 31-year-old registered nurse had ethylene glycol in her system, Coakley said. Toxicological tests after her death confirmed the finding.

But even if poisoning is undisputed, prosecutors would still have to convince a jury that Keown's husband was the culprit. Coakley declined to specify how authorities built their case against Keown.

Yesterday, James Keown's mother, Betty, of Jefferson City, said the charge against her son was groundless, and she accused Boston news media of ''crucifying him."

''He was happily married," she said in a telephone interview, the day after her son waived rendition at a Cole County Circuit Court in Missouri. ''He's coming back to Boston to face these allegations. We're ready to get this over with and to prove his innocence."

James Keown, who lived with his wife in Waltham less than a year before he returned to his native Missouri last fall, is scheduled to return to Boston today and be arraigned in court tomorrow, a spokeswoman for Coakley said.

Betty Keown said she visited the couple twice last summer -- in July, when her daughter-in-law appeared to be recovering from her symptoms, and in September, when she lay dying at the hospital.

''I was there when she passed away," Betty Keown said. Her son, she said, was devastated. ''How would you feel if your wife passed away?" she said.

Keown's lawyer in Massachusetts, Adam A. Kretowicz, also maintained his client is not guilty.

He said Keown agreed be interviewed by investigators from the Waltham police and State Police twice the month his wife died and had no objections when investigators asked to search the couple's apartment at 52 School St.

During the search, Kretowicz said, officers seized an assortment of belongings, including the contents of a medicine cabinet, trash, clothes, his wife's nursing books, and two laptop computers.

Keown knew he was a focus of the investigation, in part because Massachusetts police traveled to Missouri to question people who knew him there, Kretowicz said. Keown hired the lawyer about two weeks after his wife's death.

Still, neither Keown nor his lawyer knew that a Middlesex County grand jury had issued a sealed indictment last Thursday accusing him of murder, Kretowicz said, until police showed up at the radio station where he worked, KLIK-AM. And the lawyer said Coakley's news conference marked the first time he heard the accusation that Keown laced Gatorade with poison.

''What do [prosecutors] have now that they didn't have a year ago?" Kretowicz said. ''I haven't seen any new information from today's papers and from yesterday's press conference by Martha Coakley that I wasn't aware of in September of 2004."

Julie Keown's relatives did not return repeated phone messages yesterday.

But an old friend of James Keown who lives in Boston contacted the Globe to express shock at the accusations.

Kendra Thomas, a 27-year-old lawyer and freelance writer, said she was a freshman at Jefferson City High School when Keown was a senior. They were both on the debate team, and he was one of the few upperclassmen who was friendly to newcomers.

Keown excelled in competitions in which teams read radio scripts aloud, and he ended up hosting a show on a Jefferson City radio station while still in high school.

''He was wildly charismatic and very outgoing," Thomas said. ''He was not someone you would ever suspect of leading this double life."

Jonathan Saltzman can be reached at jsaltzman@globe.com