Update: Husband Charged Killing On-Duty Police Officer

I wonder when the last time this has happened:
From jsonline:
Benjamin Sebena, a wounded Iraqi war veteran who told investigators he had been stalking his wife for days, was charged Thursday with the Christmas Eve shooting death of his wife, Wauwatosa Police Officer Jennifer L. Sebena.
According to a criminal complaint, Benjamin Sebena told police he shot his wife early Monday after lying in wait for her for hours.
When she emerged from a break at the Wauwatosa Fire Department station on Underwood Ave., he said, he shot her in the back of her head with his own handgun and then shot her several times in the face with her service weapon, according to the complaint.
A decorated Marine, Benjamin Sebena, 30, had been part of the invasion force at the start of the Iraq War in 2003. He returned in the fall of 2004 and was sent to Ramadi.
"We were trained to kill," he says in a YouTube video made for a 2010 Christian men's conference.
"We were trained death is OK. Wasn't trained to deal with death, but we're definitely trained to kill."
In the video, Sebena claims to have killed a child in self-defense and to have watched 50 friends die in combat. He displays ropes of scar tissue that mar his knees, chest and shoulder - wounds he suffered during a mortar attack that killed a friend in February 2005. http://www.jsonline.com/news/milwaukee/husband-of-slain-tosa-officer-to-be-charged-officials-say-ek8614b-184926151.html
When this was first reported, something just seemed strange about this case.  The cop never mentioned she was out on a call and a rest place for the cops is the fire station, close to where she was found.
Clearly, this man is troubled but that is no reason why he killed his wife.
RIP to the officer and prayers to the family and officers of the Wauwatosa Police Dept.