NEW YORK (CBSNewYork/AP) — Two congressmen are calling for an “expeditious and transparent” investigation into the apparent suicide of a former Navy gunner on the grounds of a veterans’ hospital in New York.

Peter Kaisen, 76, a retired police officer from Islip, was found Sunday in a parking lot at the Veterans Affairs Medical Center in Northport suffering from a gunshot wound to the head.

His wife, Joan Kaisen, told Newsday he had been suffering from back pain so bad he was unable to sit for more than a few minutes. Doctors at Northport told her husband earlier this year there was nothing more they could do to ease his suffering, she said.

READ: Letter To FBI, VA From Reps. Peter King And Steve Israel

Tom Farley, a longtime friend and fellow veteran, told The Associated Press that Peter Kaisen visited the hospital once or twice per month but didn’t tell anyone where he was headed when he made the 30-mile trip from his home Sunday.

“We all think there is probably some depression,” Farley said. “Maybe he wanted meds. Maybe he wanted to sit and talk. I don’t know. None of the family knows.”

Kaisen’s body was found outside his car in a parking lot near a community living center at the edge of the hospital’s suburban campus just after noon Sunday, about 10 minutes after he arrived at the site, officials said.

A VA spokesman said authorities have found no signs of foul play, WCBS 880’s Mike Xirinachs reported.

A spokesman for the hospital, Christopher Todd Goodman, declined to discuss Kaisen’s patient history at the VA but said the hospital had no evidence that he sought treatment at the emergency room, entered any hospital buildings or had any interactions with staff or patients on the day he died.

“The Northport VA stands ready to cooperate with any investigative body that believes more information is needed,” the hospital’s director, Philip Moschitta, said in a statement. “At no point did the staff in this facility fail to do the right thing by our patients.”

U.S. Reps. Peter King, a Republican, and Steve Israel, a Democrat, sent a letter to the FBI and to the secretary of the Department of Veterans Affairs on Thursday asking for a “transparent” investigation into the death, following a media report — denied by hospital officials — that Kaisen had sought emergency mental health care at the hospital but had been turned away.

“It is critical that our nation’s veterans feel they can trust the services provided by their VA medical facilities, and that their health and wellbeing is of the upmost priority,” they wrote.

The FBI said it is investigating the death because it occurred on federal property, Xirinachs reported.

Joan Kaisen told Newsday her husband served on a Navy supply ship, the USS Denebola, from 1958 to 1962.

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