Riley said the security problem would be greatly reduced "if we could just educate the students to ask the easy words, 'Can I help you?'" when strangers seek to follow them inside.

Officers will also be asking residents to identify suspected trespassers from a photo array in upcoming days, Riley said.

The increased security measures follow a long chain of break-ins into Matthews rooms, culminating in last week's arrest of a trespasser who had entered an unlocked suite at 4 a.m. asking for change for a dollar.

Philip C. Liu '99, a first-floor resident, said it is "about friggin' time" that locks were installed.

"On the first floor, there are always weird people in the bathroom," Liu said. "When I'm taking a shower at three in the morning, it's kind of freaky since there's no one around and someone could just walk in."

But some Matthews residents said last week that the bathroom locks are unnecessary.

"To me it seems like the bathrooms aren't the prime issue," said Clare C. Parker '99. "I lock my room, but I'm definitely not afraid that someone will come into the bathroom."

Neil C. Magnuson '99 said the locks would be an inconvenience.

"If I forget something in the shower, I don't want to bother with the combination," he said.

Wells I. Mangrum '99 agreed.

"There's nothing they could steal in the bathroom," he said. "I'm not worried at all."

In an e-mail message, however, Dean of Freshmen Elizabeth Studley Nathans cautioned that students should use the locks wisely and not keep bathroom doors propped open for convenience.

"No lock can absolutely guarantee anyone's safety," she wrote. "Propped or unlocked doors make entry to a building or to a suite effortless; the same will be true of entry to bathrooms if bathroom locks are tampered with or if bathroom doors are propped.