FORT BEND COUNTY, Texas -

The family of a man killed in a confrontation with Fort Bend sheriff's deputies has turned over a home video of the shooting to the U.S. Attorneys' Office in Houston.

They are asking for a federal investigation to determine if the victim's civil rights were violated.

Fort Bend County sheriff's deputies arrived at Michael Blair's family home in the 7000 block of Dawn Bloom Ln in Richmond on the night of Nov. 4, 2013 after they family called 911 for help.

Blair, a 26-year-old paranoid schizophrenic, had locked himself in a bathroom with a knife, threatening to kill himself.

As the confrontation escalated, Blair was shocked with a Taser multiple times, and then, as the home video recorded by a surveillance camera shows, he was shot and killed as he lunged at one of the deputies with the knife in his hand.

According to the department's chief deputy, David Marcaurele, the officer was no-billed by a Fort Bend County Grand Jury following an investigation by sheriff's detectives and the Texas Rangers.

But Blair's mother contends the deputy used excessive force, shooting Blair almost a dozen times.

"We want him to live a long life and remember how he murdered my son," said Kimberly Blair Olaniyi.

The family said the video shows some of the shots fired after Blair was already wounded and on the floor.

"This is cold blooded execution," said Quanell X. "He was not a threat to anyone but himself. They could have left him in the bathroom."

Marcaurele said officers are trained to fired until they're sure the threat of injury or death has been neutralized. He added that  investigators learned of the existence of the video last February, after the family sent a letter of intent to file a lawsuit, and after the criminal investigation had been concluded, but family members refused to share it.

Quanell X said the video was withheld because family members did not trust the investigators.