AMHERST (CBS/AP) — The University of Massachusetts is reviewing dorm security at its Amherst campus following the alleged rape of a woman by four non-students she knew.

Three of the four Pittsfield teenagers accused of raping the 18-year-old woman on Oct. 13 were signed into the residence hall by someone who did not know them, a violation of the student code of conduct. A fourth defendant was never signed in.

A spokesman says the school will undertake a comprehensive review of dorm security measures in the next few weeks. Resident directors will also hold floor meetings to reiterate the security policy.

The university is also looking at whether the student who signed in the three suspects will be disciplined.

The suspects are being held on $10,000 bail each after pleading not guilty.