TJ Larson

The FBI has now become involved as new details have emerged about an incident where a Houston police officer shot and killed a mentally ill, disabled man. Police say 45-year-old Brian Claunch, who was in a wheelchair and had one arm and one leg, allegedly threatened, then attempted to stab another officer with a ballpoint pen.

Authorities say police responded to a call from the group home where the man lived on Saturday around 2:30 a.m., after receiving a disturbance call. When police arrived, Claunch, reportedly began making threats against the officers and refused police commands to calm down and not to move.

According to police spokeswoman Jodi Silva, the suspect advanced on one of the officers and used his wheelchair to force the officer into an area he was unable to get out of. His partner reportedly mistook a metal object in Claunch's hand for a weapon and fearing for his partner's safety and his own, opened fire on Claunch, killing him with a single gunshot to the head. The object was later determined to be a pen.

Claunch had been living at the home for about 18 months and suffered from mental illness according to the owner of the group home, John Garcia. Garcia said that Claunch, who lost one arm and one leg after being hit by a train, had a tendency to become belligerent but was usually ignored.

The officer has been identified as Matthew Jacob Marin. Marin is a veteran of five years with the Houston Police Department.

This is not the first time that Marin has shot and killed a suspect in the line of duty. According to a 2009 police report, Marin also fatally wounded another suspect. According to police records, the suspect in this incident was in the process of stabbing his neighbor to death when Martin intervened. The report said that Martin shot and killed the suspect after he refused to drop the knife he was using. Marin was also named as one of three officers involved in the alleged assault against Marvin Driver, the father of Green Bay Packers player, Donald Driver in 2008.

An investigation ruled that the shooting was justified and Marin was cleared of any wrongdoing. He and the other officers were also cleared of the assault allegations.

Marin has been placed on administrative leave, which is standard procedure when an officer is involved in a shooting.

Federal authorities have declined to comment on the matter.