Las Vegas Metropolitan police officer Kenneth Lopera has been charged with involuntary manslaughter for his role in the Mother's Day death of Tashii Farmer, authorities said on Monday.
The charges stem from an early morning incident on May 14 when Farmer approached Lopera and his partner inside Las Vegas' Venetian Hotel at approximately 12:50 a.m to complain of people chasing him. Farmer then ran away into a restricted area of the property, police said.
As the altercation escalated, Lopera punched Farmer with a closed fist multiple times -- and used a "rear naked choke" on him to stop what he believed to be a carjacking in progress, police said.
The "rear naked choke" is not department approved. Lopera applied the unapproved technique on Farmer for more than a minute, according to a statement from the police department.
The choke hold is commonly used in mixed martial arts. It's applied from behind by wrapping an arm around an opponents head while using the other arm to lock the hold in place. In a successful hold, the aggressor's elbows are brought toward each other to apply lateral pressure to both sides of the neck, cutting off oxygen.
Farmer was also tased seven times. Vegas Metropolitan Police Department Undersheriff Kevin McMahill said at a press conference in May that the number of times Farmer was tased was not part of department protocol.
"The policy...states that once the suspect has been exposed to three cycles of the Taser or the electronic control device it shall be deemed ineffective unless exigent circumstances exist," McMahill said. "Officers are taught to transition to another tool."
After Farmer was handcuffed, medical personnel were called when it was determined that he wasn't breathing. Officers attempted to resuscitate him until paramedics arrived, police said.
Farmer was transported to a local hospital, where he was pronounced dead at approximately 1:39 a.m.
Charges were filed against Lopera on Monday after the Clark County Coroner's Office ruled Farmer's death as homicide due to asphyxiation related to police restraint. The coroner also ruled that contributing factors were an enlarged heart and methamphetamine intoxication. In addition to involuntary manslaughter, Lopera was also charged with oppression under the color of office.
Lopera was placed on paid administrative leave after the incident, but will now go on unpaid administrative leave because of the charges. He also faces an internal administrative investigation in addition to the criminal investigation, LVMPD says.
CNN affiliate KTNV reports that the Las Vegas Police Protective Association paid Lopera's bail and he was released from the Clark County Detention Center.
CNN has reached out to the Association for comment.
Farmer's mother, Trinita Farmer, had been wondering where her son was when the coroners came to her house and told her on Mother's Day that he had been killed, family attorney Andre Lagomarsino said several days after Farmer's death. He lived with his mother and was the father of two young children.
The family attorney also said Farmer was taking medication for depression at the time of his death, but it was unclear what the medication was and whether it impacted Farmer's behavior, which officers said was "erratic."