The Boston Police Department reports it got a quick lead on a suspect in a Fields Corner robbery yesterday - the alleged criminal mastermind left behind his birth certificate.

According to police, a woman who'd just exited the Fields Corner T stop was walking through the Harbor Middle School yard around noon on Monday when a man approached her:

"The suspect grabbed her clutch wallet, which contained her state identification card, Charlie Card, and $40 in cash, and then fled on foot toward Dorchester Avenue. The victim stated that she noticed the suspect following her into the schoolyard, though he did not speak to her. She described him as a white male, approximately 6 feet, with a medium build, blondish brown hair, and wearing a white t-shirt and dark colored shorts.

"The victim stated that the suspect dropped two bags that he was carrying just before robbing her. The bags contained clothes, hygiene products, and a pair of sneakers. Additionally, at the top of one of the bags was a birth certificate that identified a Zachary Tentoni born in 1987, as well as a letter addressed to Zachary from his mother."

Police say about 1:35 a.m. on Tuesday, officers on patrol spotted a guy matching the victim's description at Dorchester Avenue and Faulkner Street, about a block from the robbery scene. Although he gave a different name, they contacted the victim, who arrived not long after and ID'ed him as her mugger.

Tentoni, 26, if Southington, CT, was then arrested on a charge of unarmed robbery, police say.