A Dorchester man was arrested in connection with a hit-and-run at Neponset Circle that sent a state trooper to the hospital with multiple injuries this morning.

Brandon Smith, 25, of 12 Westerville Terrace, was arrested at the Saint Francis House, a homeless shelter on Boylston Street. He's scheduled for arraignment Friday in Dorchester District Court on a charge of receiving stolen property - the car that hit the trooper.

The trooper or one of his colleagues also directing traffic got off one shot at the vehicle with Connecticut plates. The car was found not long after, abandoned on Dyer Street.

A Dorchester resident who was on the Neponset Bridge at the time saw the incident unfold:

"The car tried to cross the open median strip into oncoming traffic," he said. "Cop on detail tried to stop him and he got bumped to the ground. Two other detail cops from the intersection ran up to assist, one opened fire on the car as it sped into incoming traffic under the expressway, then took a left onto Gallivan. You could see smoke coming from the tailpipe, he driver was nailing the gas pedal. All three troopers looked kind of shocked but physically OK."

TechBoston Academy was put in "safe mode" as police swarmed the area. Service on the Fairmount Line was briefly halted as police searched the tracks near the Morton Street bridge.

State Police say the number of shots and exactly which troopers fired them remains under investigation. However, they classified the weapon discharge as self defense - about 15 minutes after another trooper lost sight of the Yaris speeding down Burgin Parkway in Quincy:

"At approximately 9:30 a.m., a motorist called State Police to say she was behind a silver car that was operating erratically heading northbound on the Neponset Street Bridge from Quincy into Dorchester. At that time, state troopers working a Neponset Street Bridge detail attempted to stop the car, the same vehicle that had been observed by the trooper several minutes earlier in Quincy. With the vehicle slowed in traffic, three troopers approached the vehicle on foot. At the bottom of the bridge, the operator attempted to flee by turning and driving into the northbound lane, against the flow of traffic. Preliminay investigation indicates two men were in the vehicle. In their attempt to escape, the car struck Trooper Scott Flaherty and narrowly missed running him over as he was laying on the ground. A trooper or troopers then discharged their duty weapons. Preliminary investigation indicates that the troopers' discharged their weapons in self-defense, in order to protect their own safety."

Flaherty was taken to Mass. General with back, leg and arm injuries, including a fracture, State Police say.

TechBoston Academy and several other schools were put into "safe mode" as the hunt progressed - classes continued as normal, but no one was allowed into or out of the buildings. Neponset Circle was shut as police investigated the incident. Red Line riders reported a high number of MBTA police on trains traveling through Dorchester.