Motive Unknown in Niagara Falls Murder-Suicide

February 27, 2013 Updated Feb 27, 2013 at 1:06 PM EDT

By Ed Reily

February 27, 2013 Updated Feb 27, 2013 at 1:06 PM EDT

NIAGARA FALLS, N.Y. (WKBW) Police are now trying to figure out why 37-year old Peter Daniels brutally killed his girlfriend, 31-year old Elizabeth Wilson, before using a shotgun top take his own life.

Investigators for the Niagara Falls Police Department say Daniels strangled his girlfriend and slit her neck with a hunting knife while she was in her home on 29th Street on Monday night.

Daniels then went across the street to his mother's house where she tried to get other relatives to come and help after she noticed her son was acting strange and had blood stains on him.

Before his mother was able to get help, Daniels returned to his girlfriend's house where he then took his own life by shooting himself with a shotgun.

A motive is still unknown, but police are looking at the possibility that the couple had a troubled relationship with neighbors reporting they heard frequent arguments and some thought Peter Daniels may have been stalking his girlfriend.

Daniels is an Army veteran who served tours of duty in the Middle-East.

Police say he was still a member of the Army reserve.

Peter Daniels was also a competitive body-builder who had won some contests late last year.

Niagara Falls Police say there are no indications that drugs played a role in the murder-suicide, but they are waiting on toxicology tests which could several weeks to complete.