It happened at around 2:30am at Healing Hands -- a group home for mentally ill patients -- on Polk at Sidney, just southeast of downtown Houston.
The owner of the group home, John Garcia, told us the overnight caretaker felt threatened and called 911 because the man began behaving erratically when the caretaker denied his request for a soda.
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"He wanted a soda at like 2 or 3 o'clock in the morning, and he kept insisting he give them to him or some cigarettes and got really aggressive, and he just called 911," Garcia said.
Police said the suspect -- an amputee with one arm and one leg -- was in his wheelchair at the time of the shooting, but was able to move freely.
Two officers entered the home and the man kept swinging an object at them. After ignoring numerous requests to drop the object, police say the man cornered one of the officers in the room.
That's when the other officer shot the man once in the head. He died at the scene.
"They both attempted to separate the suspect from the officer, but the suspect continued to swing this object at both officers," HPD spokesperson Jodi Silva said. "The other officer, Ofc. Marin, in fear of the safety of his partner and the safety of himself, discharged his duty weapon striking the suspect."
The officer who fired his weapon was identified as M. Marin, a five-year veteran of the department.
Garcia said he man enjoyed drawing on paper.
"At the table he would write on a pad of paper," he said. "He was always doodling."
The object in the man's hand turned out to be a ballpoint pen, but police said they didn't realize it until he was dead.
According to Garcia, the officers ashed the overnight caretaker to step outside the home. It was then that a single gunshot was fired inside.
Two other residents were inside the home at the time of the shooting. They were all questioned.
Garcia said the man, whose identity has not been released, lived in the house for about 18 months and was and schizophrenic and had bipolar disorder. He lost his arm and leg after being hit by a train years ago, he said.
According to Garcia, the man was capable of making a person feel threatened during a time of outrage, despite his physical state. He added that it's an everyday challenge taking care of those with severe mental illnesses.
"You just never know when they are going to go off," Garcia said. "That's all you can say. You just don't know. They can be very calm and then all of a sudden, within five minutes, it's a different dimension."
Police said the shooting will be investigated by HPD's internal affairs department as well as the Harris County District Attorney's Office.
As is standard in all officer-involved shootings, Marin was immediately placed on three-day administrative leave.
HPD records show that Marin also fatally shot a suspect in October 2009. Police say a man was attacking his girlfriend at an apartment on Winkler in southeast Houston. A neighbor tried to help the woman and was stabbed himself, police said. Officers showed up and they told the man to drop the knife. He allegedly lunged at them and Marin opened fire. The man and the neighbor who was stabbed died at the scene. The woman went to a hospital.
This shooting comes just days after Houston Mayor Annise Parker praised HPD's methods in dealing with the mentally ill.