It took only 48 hours for a first-year student's decision to register her bike with police this week to pay-off.

The student's bike disappeared from a Yard bike rack Tuesday morning, but was identified by its Harvard registration the same day in the possession of a Brighton man.

The Harvard University Police Department (HUPD) first stopped Robert Jundzil, 26, of Tremont Street in the Yard on Tuesday morning, after noticing him loitering near bike racks with a pair of bolt-cutters. After interviewing him, HUPD confiscated the bolt-cutters and sent Jundzil on his way.

But around 1:30 p.m., Cambridge Bike Shop on Mass. Ave., near Central Square, reported to the Cambridge Police Department (CPD) that a store patron was attempting to sell a suspicious bike.

Several minutes later, members of a CPD unit spotted Jundzil on Harvard Street with the bike.

The officers arrested Jundzil and charged him with having stolen property in his possession.

Officers noticed that its manufacturer serial number had been scratched off, but some of its Harvard registration sticker remained. Police could therefore trace the bike back to its owner. After a call from CPD to HUPD, the bike was returned to its grateful Apley Court owner.

"That's why we register them," CPD spokesperson Frank Pasquarello said.

Bicycle theft is one of Harvard and Cambridge's most common crimes.

HUPD officers have offered to register students' bikes for free during move-in for each of the last five years, providing a way for the bike to be recovered if stolen or lost.

"It acts as a deterrent. Do people steal registered bikes? Obviously. But generally, we don't have a lot," Catalano said.

HUPD has registered over 1,800 bikes since the program started in 1995.