Police say two men carried out a rash of robberies and attempted robberies over a two-day span in Suffolk, until the son of one of their victims and an off-duty detective helped put an end to their spree.

Investigators say Michael Burden, 38, of Holbrook, and John Giangaspro, 25, of Patchogue, carried out the robberies on Friday, Sept. 16, and Saturday, Sept. 17. According to police, the pair threatened the use of a weapon as they robbed or tried to rob multiple people and businesses.

On Friday, they are accused of holding up the Beer and Smoke Convenience Store on Sills Road in East Patchogue and the Swan Deli on South Country Road in East Patchogue. They also allegedly stole a woman's pocketbook in front of the Laundry Kingdom laundromat on Route 112 in Medford.

The following day, police say Burden robbed the CVS pharmacy on Main Street in Holbrook. Then he and Giangaspro allegedly robbed Kim's Costume Jewelry shop on Sunrise Highway in Holbrook, then stole a woman's pocketbook there. 

Afterward, they allegedly held up another woman and stole her pocketbook in the Staples parking lot on Sunrise Highway in Patchogue.

Authorities say the son of the woman who was robbed in front of Staples gave chase through the parking lot, and tackled Burden to the ground.

An off-duty NYPD detective, Brian DePalo, witnessed the robbery and chase, and helped the victim's son in apprehending Burden. Officers with Suffolk's 5th Precinct responded to the scene and took Burden into custody.

Giangaspro fled the parking lot in a vehicle, but police say they tracked him down a short time later on Hospital Road in East Patchogue. He was taken into custody.

Burden is charged with two counts of first-degree robbery, three counts of third-degree robbery and one count of first-degree attempted robbery.

Giangaspro is charged with one count of first-degree robbery, three counts of third-degree robbery and one count of first-degree attempted robbery.