Boston's police commissioner says a known drug dealer shot an officer in the leg during a traffic stop and was captured after a foot pursuit.

The officer was taken to Boston Medical Center and is expected to survive. His name was not released. Commissioner William Evans says he has been on the force for nine years and is a member of the drug unit.

The shooting occurred at about 10:30 a.m. Friday in the city's Dorchester neighborhood, on a residential side street lined with single- and multi-family homes. Evans says the gun used in the shooting was recovered.

Evans says the suspect, identified as 27-year-old Grant Headley, was on probation after being released from prison in April and was driving on a suspended license.  (Associated Press)