Suspect in Texas deputy shooting has history of mental illness

New details emerged from Monday's court proceeding

Shannon Miles is escorted out of a Houston courtroom on Monday. (Pat Sullivan/Associated Press)

A man charged with the ambush and killing of a Houston police officer was once declared mentally incompetent.

Shannon J Miles, 30, was sent to a state mental hospital for several months in 2012. Miles was charged with aggravated assault with a deadly weapon after fighting over a remote control at a homeless shelter, the Associated Press reported.

He was ruled mentally incompetent to stand trial by North Texas State Hospital in Vernon, Texas. The charges were later dropped when the victim could not be reached.

Surveillance video shown in court on Monday showed a man killing Deputy Darren Goforth by shooting him once in the back of the head and unloading 15 shots into the officer’s back.

The lack of motive has caused Harris County sheriff Ron Hickman to speculate the unprovoked killing.

“We've heard black lives matter. All lives matter. Well, cops' lives matter too," he said during a press conference. "At any point where the rhetoric ramps up to the point where calculated cold-blooded assassination of police officers happens this rhetoric has gotten out of control.”

Conservative pundits have ran with Sheriff Hickman’s comments, blaming the senseless killing on the Black Lives Matter movement, who have vehemently condemned the killing, simply because the suspect is black. BLM advocates seek policy reforms that would result in safer policing across the US.

Mr Miles' next court date is 5 October.