The burglars apparently made off with at least 25 laptops and other expensive items. Several doors in the building were pried open.
The University said it's facing around 50 thousand dollars in replacement and damage costs.
"It's a pretty safe campus, so it was surprising to hear that," Karina Revilla, a UC Merced student.
Parts of the library are closed off to students while police collect evidence and crews repair or replace busted doors.
"It's the worst possible time with finals and everybody trying to get stuff done. And parts of the library shouldn't be closed down," said Freshman Matthew Stillwell.
Brenda Ortiz, a public information officer with the university, said the crooks navigated their way through the most of the building. They broke through several hallway doors. Their first stop was the book store.
"The individuals them pried open that door and stole electronics, including iPods," Ortiz said. "Then it appears they went up to the third floor of the library, into a computer lab, and stole about 25 laptops from that lab."
Now all that's left in the computer lab is nearly empty tables and computer parts left behind by the suspects. "This is the first incident of forcible entry into our buildings since the campus opened in 2005," Ortiz noted.
It appears, Ortiz said, the crooks knew exactly what they wanted and where to go for it. They only took expensive electronics. And aside from damaged or boarded up doors everything else was left untouched.
At this point, the university is not sure whether the heist was pulled off by students.
Ortiz said campus police did spot two people running from the library shortly after the break in was reported. But policy prevents them from chasing anyone if only one officer is on duty.