Students walking from class on Regents Drive.

On his second night in College Park, Ruben Ortega decided to go to a party with his friends.

The freshman aerospace engineering major brought his backpack, filled with his phone, wallet, university ID and other valuables, he said. When he was told he couldn’t bring it into the party, Ortega hid the bag in a bush around the corner. Half an hour later, it was gone.

“I called the cops, and they said all I could do was make the report that the stuff was missing,” Ortega said. “I trust the world way too much.”

Ortega is not the only victim of theft at the University of Maryland. According to annual crime report statistics, theft is the most frequently reported crime on the campus, with 347 instances reported last year.

In response to this trend, University Police’s Strategic Enforcement Response Team sends officers around the campus in plain clothes to respond to incidents and conduct investigations, said University Police spokeswoman Sgt. Rosanne Hoaas.

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SERT, which started in fall 2006, is made up of four officers and a supervisor who focus on street crime and trends in the area, Hoaas said. Officers in the unit work with road officers as well as cameras placed around the campus to try to reduce theft.

“It allows us to get much closer to a potential suspect or a potential victim,” said Master Patrol Officer Patrick Dykstra, a former SERT member. “We get to observe the environment without disturbing it.”

In part because officers are able to go undercover, the number of thefts that occur on the campus has decreased, Dykstra said. In the program’s inaugural year, there were 580 reported thefts.

If a SERT member witnesses a crime taking place, the officer identifies him- or herself and conducts a brief investigation before making an arrest, Dykstra said.

“People are more likely to believe that we’re students,” Dykstra said, “and they’re much more likely to commit a crime when they don’t know anyone around them.”

University Police Chief David Mitchell said controlling theft is difficult at this university because of its size.

“It’s the toughest crime to deal with in volume,” Mitchell said. “You have to consider the size of the campus. … Thefts happen every single day.”

This university also has an open campus, Mitchell said, and students are not the ones who commit many of the thefts at this university.

“Many people come to the campus just to steal things,” Mitchell said, “and we know this because we catch them.”

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Despite the obstacles, Dykstra said, eliminating crime completely at this university could be possible.

“Most of these crimes are crimes of opportunity,” Dykstra said. “People should care for their items as if there’s a possibility that they’ll get stolen.”

CORRECTION: Due to a reporting error, a previous version of this story identified Master Patrol Officer Patrick Dykstra as a SERT member. He is a former SERT member. The article has been updated.