BOSTON -- A convicted rapist wanted by police for failing to register as a sex offender was arrested on Saturday with the help of a Massachusetts state police dog.

Michael Perry, 38, who served a state prison sentence for aggravated rape and is classified as a high-risk Level 3 sex offender by the Sex Offender Registry Board, was on the list of the State Police Department's Most Wanted Sex Offenders.

Officials learned that Perry was planning to meet his mother near Wellington Circle in Medford on Saturday night. Troopers from the fugitive unit, along with a K9 unit and troopers assigned to the Medford barracks, established surveillance of the area.

Shortly before 7 p.m., State Police observed the suspect's mother drive into the Wellington MBTA station. At 6:57 p.m., troopers observed Perry get into his mother's car and immediately converged, boxing in the car with their own vehicles and ordering Perry to surrender.

Perry got out of the car and tried to run from the troopers, who ordered him to stop. When Perry ignored their orders, the K9 trooper deployed his dog, "Drago," who apprehended the fleeing suspect.

Police took Perry into custody and had him transported to Massachusetts General Hospital for treatment of a laceration to his leg suffered when the dog took him down. He was treated at the hospital and placed into the custody of the Essex County Sheriff’s Department.

In Perry’s possession, State Police found two photo identifications issued to different women, one a North Carolina license, the other a Massachusetts Registry of Motor Vehicles ID card. The investigation into why Perry was in possession of the identification documents is continuing.

In 1993, he was convicted of aggravated rape in Middlesex Superior Court and served a state prison term. He was convicted in Lynn District Court in 2005 for failure to register as a sex offender, and received a 2-½ year suspended sentence. Perry violated conditions of his probation for that conviction by again failing to register as required, prompting the issuance of the warrant on which he was arrested Saturday, police said.

Perry is expected to be arraigned in Lynn District Court and could be ordered to serve the 2-½ year sentence from 2005.

According to his wanted poster on the State Police Most Wanted Sex Offenders Web site, Perry’s criminal record includes several entries for violent crimes in Massachusetts and Florida.