MILWAUKEE - Milwaukee police have taken a man into custody for allegedly masturbating in a bathroom stall at the Milwaukee Public Museum. The suspect was arrested Thursday when he returned to the Museum. A group of sixth graders on a field trip went inside a men's restroom. They said they heard the man masturbating, and also noticed a number of porn magazines on the floor around the man's feet. The boys ran out of the bathroom and told a mother who was chaperoning the group. That woman, who would only talk to TODAY'S TMJ4 on the condition of anonymity, told reporter Shelley Walcott: "I walked in and I was like, 'Oh my gosh,' and it was true. I mean he was doing something because he was moaning." Museum officials were alerted. A security guard and another museum employee talked to the man, but he ran off before police arrived. It's what the man said that really worried the chaperone. "He said to the security guard and another gentleman from the museum that he comes in here every day and it doesn't seem to be a problem and why is it a problem today?" the chaperone said. The museum says they have beefed up security, and even though officials say the museum is safe, they want to remind patrons to be as careful there as they would in any other public place.