BOSTON >> It didn't take Boston police long to track down three suspects in an armed convenience store robbery.

Authorities say the men were all wearing court-ordered GPS devices for unrelated cases, which placed them inside the Dorchester store and allowed investigators to track them to an apartment a block away.

Police say the suspects entered the store at 6 p.m. Wednesday. All three wore masks and one had a gun.

They made off with cash and cigarettes.

All three pleaded not guilty at their arraignment Thursday. Two had their bail revoked in prior cases. A third was held on $50,000 bail.

The prosecutor said "all their GPSs pinged to the store at the time of the robbery." Police also found evidence in the apartment that tied them to the robbery.