Officer Who Led to George Floyd's Death 'Tried to Kill' Black People Before

The Minneapolis police officer seen kneeling on the neck of an unarmed black man heard saying "I can't breathe" multiple times before he died was a 19-year department veteran who was the subject of at least a dozen police conduct complaints that resulted in no disciplinary action and one that led to a "letter of reprimand." The officer, who was praised for valor during his career, also once fired his weapon during an encounter with a suspect, records show, NBCNews reported.

The officer, Derek Chauvin, and three fellow officers were fired Tuesday from the Minneapolis Police Department, one day after the incident involving George Floyd, whose cries of physical pain were recorded on a cellphone video and whose death led to a wave of violent protests Wednesday night in Minnesota's largest city. Minneapolis police identified the other officers as Thomas Lane, Tou Thao and J. Alexander Kueng.

Local and federal authorities spoke at a joint press conference on Thursday, which was delayed for two hours after reports of charges possibly being announced, but no such announcement came. Representatives from the U.S. Department of Justice, FBI, the Minnesota Department of Public Safety, along with Hennepin County Attorney Michael Freeman, offered no significant updates other that to promise a swift and thorough investigation of the officers.

To be the subject of a dozen complaints over a two-decade career would appear "a little bit higher than normal," said Mylan Masson, a retired Minneapolis Park police officer and longtime police training expert for the state of Minnesota at Hennepin Technical College.

But, she added, anyone can file a complaint against an officer, whether or not it's valid, and officers might be subject to more complaints if they deal with the public often. Either way, an officer's disciplinary record will be up for scrutiny in any legal proceedings, Masson said.

An investigation including state authorities is being led by the FBI. Chauvin, 44, who is white, is being represented by lawyer Tom Kelly, who declined to comment when contacted by NBC News. Efforts to reach the other officers for comment were unsuccessful Wednesday.

National Fraternal Order of Police President Patrick Yoes said Thursday that authorities must ensure justice is served in Floyd's death, "whatever the consequences."

"The fact that he was a suspect in custody is immaterial — police officers should at all times render aid to those who need it," Yoes said. "Police officers need to treat all of our citizens with respect and understanding and should be held to the very highest standards for their conduct."

Chauvin, who joined the Minneapolis Police Academy in October 2001, has had a career that included use-of-force incidents and at least one lawsuit related to an allegation of violations of a prisoner's federal constitutional rights.

In 2006, Chauvin was one of six officers from the Third Precinct who responded to a stabbing at a Minneapolis home. Police said Wayne Reyes stabbed his friend and his girlfriend and then threatened to kill all of them with a shotgun.

Police pursued Reyes, who fled in his truck. He got out of the vehicle with a shotgun, and "several officers fired multiple shots," killing Reyes, police said in a report.

It was unclear during the initial investigation which officers fired their weapons and whether Reyes had made any verbal or physical threats.

All of the officers, including Chauvin, were put on paid leave during an investigation, which is standard protocol. It is unclear what happened with the investigation, and Minneapolis police did not immediately respond to a request for Chauvin's service record.

The same year, Chauvin and seven others were named in an unrelated federal lawsuit filed by an inmate at the Minnesota Correctional Facility at Lino Lakes. Further information was not immediately available; records show that the case was dismissed without prejudice in 2007.