Deschutes County Sheriff via AP Lawrence Loeffler, 86, shot his wife once in the neck and then again in the head in what he described to investigators as a "kill shot" to make sure she was dead, according to a prosecutor. Loeffler's lawyer says he's not guilty of murder because he was suffering from delusions.

BEND, Ore. -- An 86-year-old Oregon man on trial for the shooting death of his wife carried out the attack after a series of grievances with his family that prosecutors said included the failure of his stepdaughter to wish him a happy birthday and his complaint that his wife put the lid on the ketchup bottle too tightly.

Deschutes County prosecutor Mary Anderson told jurors about Lawrence Loeffler's complaints during opening statements Wednesday at his murder trial.

Anderson said Loeffler made the criticisms about his family during questioning by officers about the death of 83-year-old Betty Loeffler. The prosecutors said the killing was a calculated act.

Anderson said Lawrence Loeffler took the phone off the hook, retrieved a .25-caliber handgun in the middle of the night from the bedroom where she slept and then "set a trap" to get his wife onto the deck at the back of their house near La Pine, a town of about 1,670 people on the east edge of the Cascade Range in Central Oregon.

He shot her once in the neck and then again in the head in what he described to investigators as a "kill shot" to make sure she was dead, Anderson told jurors.

While Lawrence Loeffler admitted having planned to kill his wife, defense attorney Jacques DeKalb said his client was not guilty of murder because he was suffering from delusions.

"He had no idea what reality was at that time," DeKalb told jurors.

DeKalb said Lawrence Loeffler spent about 10 days in a Bend retirement home after surgery to remove his gall bladder in December, receiving hospice care. He said Loeffler was fixated on the death of his own father and became disoriented, irrational and obsessed with death.

On Wednesday, jurors listened to a 911 call Loeffler made after the shooting. During the recording, the dispatcher asks Loeffler about the shooting, and he says his wife was threatening him and he was afraid for his life, so he shot her.

Some of the call is nearly impossible to understand as Loeffler sobs and screams repeatedly that he doesn't know the details of what had taken place in the home.

Lawrence Loeffler breathes with the help of an oxygen concentrator, and he began to cry as he sat at the defense table listening to the call.

The Associated Press