By Dave Sherwood
PORTLAND Maine (Reuters) - (This June 11 story was corrected in 11th paragraph to say it was a woman, not a man, who starved a 5-year-old in 1995 case)
A 75-year-old man who police say shot and killed two teenagers in Maine after a dispute over shoveling snow in a parking lot will plead not guilty by reason of insanity, according to the state attorney general's office.
James Pak, a stone mason and landlord from Biddeford, Maine, had initially pleaded not guilty to two counts of murder in March 2013, but added insanity to his plea after a battery of recent mental health examinations, his lawyers said.
The "insanity defense" is invoked in just 2 percent of cases and successful just one in four times, according to Ann LeBlanc of Maine's State Forensic Office. Defendants declared insane are treated as patients, not criminals, she said, but are committed to psychiatric wards indefinitely.
"It's not a get out-of-jail free card," said LeBlanc. "If you're found guilty of a criminal offense, you can calculate your date of release, but not when you're found insane."
Police were called to the apartment Pak had rented to Derrick Thompson, 19, and Alivia Welch, 18, in December 2012, after Pak threatened to shoot Thompson, prosecutors said.
Officers left believing the situation had been resolved, but minutes after they departed Pak shot and killed Thompson and Welch, according to police reports.
Pak then barricaded himself inside his home, part of the same apartment complex, and said he was suicidal, police contend.
Defense lawyers told Reuters Pak fled Korea as a teenager during the Korean War, and had lived in a foster home in California and eventually, Vermont, where he ran a successful garden and stone mason business.
"He has an incredible life story, and for it to end like this is just a terrible tragedy for everyone involved," said Lawrence Goodglass, one of Pak's attorneys.
The Maine Attorney General's office declined to comment on details of the case.
Maine has seen a few instances in which defendants have successfully pleaded insanity, including the 1995 case of a woman who suffered from schizophrenia who starved her 5-year-old daughter to death and a 2006 incident in which a western Maine man killed his mother with a hatchet.
"These aren't typical who-done-it cases," said defense attorney Goodglass. "It's a question of whether or not the defendant understands the wrongfulness of his conduct at the time of the crime."
(Editing by Scott Malone and Jim Loney)