The officer, a nine-year veteran of the force assigned to a drug control unit in the city's Mattapan neighborhood, had attempted to pull over a man that Police Commissioner William Evans said "was well known to police" as a drug dealer and was driving with a suspended license.
"He is out on probation and he is out selling drugs, and that's why he was pulled over," Evans said during a news conference today at the hospital where the officer is being treated. The officer has yet to be named.
After police pulled over the suspect, Grant Headley, 27, he jumped out of the vehicle, spun around and shot the officer in the leg and ran, Evans said. Headley, who was just released from prison after serving a three-year sentence on gun and drug charges, was apprehended after a short foot pursuit, Evans said. Police recovered the weapon they believe was used in the shooting.
"The officer told me from his bedside that another officer applied a tourniquet and it stopped the bleeding," Boston Police Patrolmen's Association President Pat Rose told ABC News.
That officer was Rose's son-in-law, and the EMT who transported the shot officer was Rose's son, he said. "These are our neighborhoods."
Boston Police received 1,500 tourniquets and began training in their use in the months after two bombs were detonated along the finish line of the Boston Marathon, killing three -- including 8-year-old Martin Richard -- and wounding 260 others.
The officer remains in the intensive care unit at Boston Medical Center but is expected to make a full recovery, Evans said.
Mayor Martin Walsh visited the officer at the hospital and told reporters that the officers in his department are the "best in the nation. ... I commend the officers for their incredible restraint."