DENTON, Texas (CBSDFW.COM) – The attorney representing the family of a 23-year-old student tased and fatally shot by a Denton police officer in January, says he was experiencing a mental health crisis when he was killed.

Darius Tarver (Credit: Family Photo)

Civil rights attorney Lee Merritt is demanding justice for Darius Tarver.

In a release, Merritt questions officer’s treatment of Tarver that night, saying, “The mentally impaired are among the most vulnerable communities in our society. First responders are required to recognize signs of mental health crisis and engage citizens suffering such episodes with care and professionalism. The goal is to get them help while ensuring the safety of the community and law enforcement personnel.”

Tarver was involved in a near fatal collision shortly before he was killed where he sustained a traumatic brain injury. He was prematurely released from ICU, according to Merritt, and subsequently began to exhibit signs of significant mental impairment. On the day he was killed, he barricaded himself in his room while muttering to himself about God and light. Thus, his roommate called the police and asked for help.

Video shot from four police body cameras that night show Tarver holding a large knife and frying pan when police approached him near the outside stairwell of his apartment building, The Forum at Denton Station.

When Tarver did not follow commands to drop the items, an officer shot him with a taser. Tarver stumbled toward officers, and one officer fired a single shot in his direction.

After several seconds on the ground, Tarver got back up, retrieved the pan and advanced toward officers again. That’s when the same officer fired two more times, killing him.

Police Chief Frank Dixon defended his officers, saying they acted professionally. He was critical of those who questioned the officer’s decisions in the shooting.

But Merritt says Tarver’s roommate told police that Darius wasn’t violent or threatening — but his behavior was increasingly bizarre.

When he encountered the police he declared “I am not afraid! There is only One God and he will be my shield!”

Merritt claims responding officers were “poorly trained and ill equipped to respond to the crisis,” which resulted in Tarver’s death. 

WATCH: Denton Police Release Video Footage Of UNT Student Darius Tarver’s Fatal Shooting