BROOKFIELD, Ill. — Police made an arrest Wednesday after a threat was called into Brookfield Zoo Tuesday evening, causing the facility to lock down.

Police said the suspect was located at her home in Chicago and has been charged with one count of disorderly conduct. More charges could come, investigators said. She was also evaluated by a crisis worker and sent to an area hospital for possible further mental health treatment.

No name or age was given for the female suspect. Police believe at around 5:15 p.m. Tuesday, she called a crisis intervention line and “threatened to do harm to herself and others at the zoo.”

As a result of the call, police locked down the zoo and a shelter-in-place order for guests was given. Over 50 officers from various jurisdictions responded and a “methodical” sweep of the zoo was conducted.

The caller was not found and all zoogoers were safely escorted out following an “all clear” designation at 7:30 p.m. 

In a press conference Tuesday night, police said the FBI was involved in the investigation.