DETROIT – Mich. – A Detroit police officer has been suspended with pay after a bystander’s video showed him punching a possibly mentally ill woman at least 10 times at a hospital, the police chief said.

Detroit Police Chief James Craig has called the video “very disturbing” and said a criminal investigation has been launched into the officer’s use of force. But he also added the officer is entitled to due process. The department is not making any conclusions but observations, Craig said.

Craig did not publicly identify the officer in the video, and CNN has not been able to identify him or get comment from him or his attorney. CNN has reached out to the Detroit Police Officers Association for comment.

During a press conference Thursday, Craig detailed how the incident unfolded on Wednesday night.

The initial call

Craig said police responded to a “lewd and lascivious in progress” call around 6:45 p.m. Wednesday. The woman was walking around the neighborhood naked, according to a report from CNN affiliate, WXYZ.

The woman was not agitated but passive, Craig said.

The officers did not handcuff the woman and Craig said that was among his concerns.

“We know from our training and experience anytime we transport someone, particularly if they are suffering from mental illness for their safety and for the officers’ safety and the community’s safety that we handcuff,” he said.

The officers gave the woman a robe to cover herself and placed her in the car. They then took her to Detroit Receiving Hospital.

The incident took a turn

When the woman — who has not been named — arrived at the hospital she became agitated and took off the robe, Craig said. She spat on hospital employees, bit a security staffer twice, and tried to bite the officer who later repeatedly punched her, Craig said.

The bystander video shows the officer, his partner and two security guards trying to control the woman.

According to the chief, the incident took a turn when the woman turned her back toward the officer who had hit her.

“At that point we have grave concerns for the officer’s actions,” he said.

Officers should not continue to use “hard hands” on someone who turns their back, Craig said.

The video shows the officer continued to swing at her at least 10 times. The woman was treated for minor injuries and had bruises, the chief said.

Investigations ongoing

Craig said officials are in the process of downloading body camera footage and that video “tells a little bit of a different story.” When asked about the video, the chief said use of force “never looks good” to the public.

But he said the bystander’s video was troubling because officers are taught to de-escalate, and there are parts of the recording where it appeared the officer did not do that.

The bystander video was provided to a Detroit television station, which gave the footage to police on Wednesday.

Neither the officer — described only as an 18-year veteran — nor the person who recorded the video have been interviewed. But Craig said that members of the hospital staff were interviewed and confirmed the woman became agitated and aggressive. The staff did not comment on the officer’s use of force, he said.

The police chief also said the suspended officer has had six minor use of force incidents before, the most recent in 2015.