The victim's family gave Eyewitness News the video, and say they plan to give it to the FBI, too, calling for a new investigation.
Family members claim video shows 26-year-old Michael Blair just moments before he was killed by a Fort Bend County deputy in November. The 20-minute video shows two investigators responding to a man locked in a bathroom after they kicked in the door.
"Drop the knife, drop the knife!" you hear an officer saying.
They ask him to drop a knife a least 50 times, then shock him with a Tazer.
"I want to help you, let it go. I cannot help you until you drop that knife down," the officer says.
Blair appears to lunge at them and the deputy fires his gun 11 times, killing Blair.
"All we're asking is that someone recognize what we recognize. That was brutality," Blair's mother, Kimberly Blair Olaniyi, said.
Blair's family and community activist Quanell X released the video in a press conference Wednesday, claiming it shows police brutality. They won't say where they got the video or how long they've had it. They didn't offer this up during the initial investigation.
"These cases are always lies and truths aren't told. So that tape was held until they would finish their -- quote unquote -- investigation," Quanell X said.
A grand jury no-billed the investigators seen in the video, but a spokesperson for the sheriff's office says this is still an open case and the office will review any new evidence provided, including this video.