A recent report uncovered "utter chaos" in the frantic first moments in a search for a gunman who carried out a mass shooting in Maine.

The Portland Police Department report looked into the response after Robert Card killed 18 people and wounded 13 others at a bowling alley and a bar in Lewiston. Both the Cumberland County Sheriff's Office and Portland Police Department tactical teams were responding to the spot where Card's vehicle was abandoned by the Androscoggin River.

Among those who joined the search was a group of deputies who had been drinking and nearly crashed their armored vehicle, according to the after-action report obtained by the Associated Press.

Others showed up in civilian clothes and could have been mistaken for the suspect creating a dangerous situation where officers could have opened fire on each other.

Tactical team leader Nicholas Goodman said in the report that the officers who showed up without orders risked doing more harm than good.

"I have never seen the amount of self-dispatching, federal involvement with plain clothes and utter chaos with self-dispatching in my career," Goodman wrote.

Daniel Wathen, the chairperson of an independent commission investigating the shooting, called them "disturbing allegations."

He said some issues may be outside the panel's scope, including the allegations of drinking. The nine-page report, which was partially redacted, was obtained by the AP through the state's Freedom of Access Act.

Card's body was found two days later after the mass killing. He died by suicide.