LOS ANGELES (CNS) — Sheriff Alex Villanueva expressed "grave concerns" Friday night about the shooting by a deputy of a knife-wielding 34-year-old man in the midst of a mental health crisis, a killing that was captured on videotape and prompted a federal lawsuit from the man's family.

David Ordaz Jr. was shot and killed in East Los Angeles on the afternoon of March 14 after family members called for help during a crisis during which the man was holding a knife and appeared suicidal.

In a statement posted on the sheriff's department website Friday evening, Villanueva wrote that deputies had responded to a call of a man with a knife "who was under the influence of drugs and wanted to commit 'suicide by cop."'

Also Friday, the sheriff's department released footage from body-worn cameras showing several deputies shoot and killed Ordaz as family members stood in their yard a few feet away. Footage of the shooting taken by a pedestrian was previously posted on YouTube.

"I want to clearly state I have grave concerns regarding this deputy involved shooting," Villanueva wrote. "One of the deputies has been relieved of duty and their peace officer powers have been suspended, pending the outcome of this investigation."

The sheriff wrote that the results of an internal investigation will be submitted to Los Angeles County prosecutors, who will "determine the legality of the shooting. Additionally, the investigation will be shared with the Los Angeles FBI Field Office for their review."

A federal civil rights lawsuit filed by the Ordaz family Thursday alleges that deputies used unjustifiable lethal force when they shot and killed Ordaz. After the filing, an LASD spokeswoman said the department would not comment on pending litigation.

Videotapes of the shooting appear to show Ordaz, after being hit with non-lethal rounds, turning to flee down the sidewalk. Deputies allege Ordaz lunged at them, prompting lethal force, according to the complaint for wrongful death and civil rights violations.

"In fact, the coroners report shows that all of the bullets except two, struck him on the back and on the side and the final bullet as visualized in the video shows a helpless David Ordaz Jr. looking up from the pavement without any weapon, and the killing shot was fired into his chest," the lawsuit alleges.

Body-worn camera footage indicates that at least 10 rounds were fired, including a single shot fired immediately after the flurry of gunfire had stopped and Ordaz was lying face up on the sidewalk, holding his shoulder.

Ordaz's family contends in the suit that four LASD deputies — Remin Pineda, Edwin Navarrete, Jaime Romero and Nathaniel Trujillo — "carelessly managed, maintained, operated, controlled, and supervised" the incident. Villanueva did not name the deputy who had been relieved of duty.

Instead of de-escalating the situation, deputies fired multiple bullets, instantly killing the father of three, attorney Federico Sayre contends.