MINNEAPOLIS (WCCO) — Brooklyn Park police say they’ve made an arrest after a 6-year-old boy was sexually assaulted inside a portable bathroom at a city park Wednesday evening.

Family members told police that the boy went missing during a party at Willowstone Park, and was later seen leaving the bathroom at about 9 p.m., followed by a man in his early 20s.

(credit: CBS)

A family member confronted the man, who told them the boy got stuck in the bathroom so he was helping him. Later, the boy said the man sexually assaulted him.

Police said they believe the man in custody frequents the park. He was not identified by name but was described as 18 years old.

Police believe the man they have arrested will be formally charged on Tuesday.

“The Police Department extends a sincere thank you to all the community members who assisted in this investigation,” the department reported.