(KRON) — A 33-year-old man was arrested after trespassing at Mill Valley Middle School and entering the girl’s restroom on Oct. 30, according to the Mill Valley Police Department. There, police said he blocked the door behind him, exposed his genitalia, and masturbated in the presence of students.

At 4:30 p.m., Mill Valley police responded to a report of a person loitering at the middle school located at 425 Sycamore Avenue. At that time, authorities said they learned that the suspect, identified as Derrell Bland, had entered the female restroom and talked to students inside. Once police located Bland, he was cited for trespassing, removed from the area and released.

It was later Monday evening that concerned parents contacted Mill Valley PD about the incident and provided more details about what had allegedly happened in the restroom that day, including Bland masturbating in front of students, the police department said. Investigators said that when the suspect blocked the door, the girls inside the restroom reported feeling as though they were being imprisoned with no means to escape.

A day later, on Oct. 31 at around 1 p.m., Bland was being contacted by Tiburon Police Department officers for an unrelated case, MVPD said. Mill Valley police requested that the Tiburon officers detain Bland, and MVPD arrested Bland shortly after.

Bland was charged with trespassing, felony indecent exposure within an inhabited building, felony annoy/molest a child under the age of 18 within an inhabited building, false imprisonment, loitering within a public bathroom to engage in any lewd or lascivious act and engaging in lewd conduct in a public place. He was booked into Marin County Jail.

Mill Valley police said additional charges are possible.