NYPD takes dozens of Columbia University protesters into custody. Watch live coverage.

NEW YORK — The NYPD took dozens of protesters at Columbia University into custody Tuesday night.

Police began moving in around 9 p.m. after receiving permission from the school to enter. A massive police presence had built up outside the school before officers moved in. 

A dramatic scene unfolded as the NYPD brought in a large vehicle with an extendable ramp to gain entry to a second-floor window of Hamilton Hall, which schools officials said was occupied by protesters. Around 9:30 p.m., dozens of officers wearing helmets began to enter the building through a window they had pried open. Additional crowds of officers entered campus on foot through the main gate.