University of Massachusetts police arrested a Vermont man they say has been pilfering laptops from students at the Amherst campus’s main library. Christopher Desjardin, 30, of Colchester, Vt., was arrested this week after a stakeout at the W.E.B DuBois Library. He was a suspect because he looked older than the students and was spotted in the building during previous thefts, police said. Deputy Police Chief Patrick Archbald told The Daily Hampshire Gazette that officers saw Desjardin appear to take an item and followed him to his vehicle. He was charged with larceny over $250, although police think he might be responsible for a dozen of thefts of unattended laptops.