Detroit Police Chief James Craig suspended an officer caught on video brutally punching a naked hospital patient suspected to be suffering from a mental crisis about 6:45 p.m. Wednesday, Aug. 1.

A criminal investigation has also been initiated with the Wayne County Prosecutor's Office, he said.

Video of the incident was recorded by a Detroit Receiving Hospital employee and provided to WJBK-TV, Fox 2 News, as well as police administration.

Craig called the incident "troubling" but hasn't said the officer acted inappropriately.

"Certainly, the suspect in this case became very agitated; she was threatening, clenched fists, she spit on several of the hospital employees," the police chief said. "in addition to that, a member of the security staff was bitten twice and sustained some injury.

"At some point, she tried to bite the officer who used force, so as he was trying to calm her down, at some point, the officer started to strike her because she was not responding, she was not compliant."

Craig said the speed at which the officer escalated to repeatedly punching the woman, as well as the continued strikes delivered after she turned her back, are concerning.

"At this point, I can't tell you why the officer didn't opt for using a Taser, why he didn't wait for backup, but those are the things that we'll be determining throughout this investigation," the chief said.

Craig said the woman was treated for minor injuries.

Chief Craig updates media on Use of Force incident involving a Detroit Police Officer. Upon notification of this incident a criminal and internal investigation was immediately launched. The officer has been suspended. The department is working closely with the Wayne County Prosecuting Office. Posted by Detroit Police Department on Thursday, August 2, 2018

The officer, a corporal now on paid administrative leave, is an 18-year veteran of the department who has had no major use-of-force complaints filed against him; however, he does have six lesser use-of-force complaints on his record, the chief said.

Craig says the department is reviewing body-cam videos and will release it at "the appropriate time" following completion of the criminal investigation.

Police initially responded to a "lewd-and-lascivious" call involving the naked woman who was believed to be suffering from a mental episode. She was "passive" during transport to the hospital and became agitated after arriving at the hospital.

Craig says Detroit police respond to an average of 500 calls per month involving mentally ill suspects.