Police arrested four Trinity College students Sunday morning who allegedly broke into Morse College and sprayed fire extinguishers in the college’s library and students’ rooms.

University Police Lt. Michael Patten said all four will be charged with criminal trespassing and one, Brannon Knott, faces charges of reckless endangerment, breach of peace and criminal mischief. Knott is the student who allegedly wielded the fire extinguisher.

Patten declined to release the names of the other students.

Morse College Master Frank Keil said students are taking inventories of the damage to their rooms, but estimates are not yet available.

“They made a tremendous mess and students were obviously very upset,” Keil said.

Students called police on Sunday at 3:25 a.m., describing the break-in to the library and requesting assistance. When police arrived at the scene, several students pointed officers in the direction of Knott as he was leaving the courtyard, Patten said.

According to police, Knott sprayed two fire extinguishers in the library and aimed them under doors into student rooms. Knott allegedly went through multiple entryways on the second floor and some rooms on the first floor. Some of the students were asleep at the time of the incident, Patten said.

The discharge, a powdery substance, is an irritant but not hazardous, he said.

Knott and the other three suspects said they were visiting friends, but they could not tell police who the friends were, Patten said.

Police believe the perpetrators were probably let through the main college gate by an unsuspecting student, Patten said. The four are believed to have entered through entryway doors which were propped open.

This incident prompted the college community to become more vigilant about securing their personal belongings by locking their doors, Keil said.

“We’re going to try to urge people to lock the entryway doors,” Keil said. “It was certainly an outside thing, but we have to be careful.”

While there have been other incidents of vandalism involving fire extinguishers in the past, there have been none on this scale, Keil said.

Morse resident James Barton ’07 said that the timing of the break-in was unfortunate because it coincided with the Morse Screw. But he said that students are continuing to go about their daily routines.

“We’re upset, but there’s nothing much you can do about it,” Barton said.

The four students were released on a promise to appear in New Haven Superior Court Oct. 13.