Mary Sullivan was walking her black Labrador earlier Friday night when gunshots rang out in her neighborhood.
"I'm glad it's over," she said. "The city and the people have gone through so much pain over these irrational decisions of these young men."
The manhunt began late Thursday just hours after the FBI released photos of the two suspects in the marathon bombings.
"Investigators are recovering a significant amount of homemade explosives" from the scene of the shootout, Procopio told CNN.
It was not immediately clear what explosives were recovered, but the discovery followed a tense night in which authorities say the brothers allegedly hurled a homemade grenade and five pipe bombs at pursuers after killing an officer and hijacking a car.
Tamerlan Tsarnaev, 26, was wearing explosives and a triggering device when he died, a source briefed on the investigation told CNN on condition of anonymity.
The manhunt brought Boston to a near standstill. The Boston Red Sox announced they were postponing Friday night's game against the Kansas City Royals "to support efforts of law enforcement officers." NHL's Boston Bruins also postponed its game against the Pittsburgh Penguins.
The city's subway, bus, Amtrak train and Greyhound and regional Bolt Bus services were shut down. Taxi service across the city also was suspended for a time during the manhunt. Every Boston area school was closed.
Boston's public transit authority sent city buses to Watertown to evacuate residents while bomb experts combed the surroundings for possible explosives.
Initially, authorities said the brothers started their rampage by robbing a convenience store. By late Friday, the Middlesex District Attorney's office backtracked on the allegation, saying an investigation determined that the robbery at a 7-Eleven was unrelated.
The violent hours leading up to the capture began in Cambridge, across the Charles River from Boston, MIT officer Collier was shot and killed while he sat in his car on Thursday night, the Suffolk County District Attorney's Office said in a statement.
The two suspects, according to authorities, then hijacked a vehicle at gunpoint in Cambridge, telling the driver that they were the marathon bombers, a law enforcement source told CNN.
At some point, apparently at a gas station, that source said, the driver escaped.
Police, who were tracking the vehicle using its built-in GPS system, picked up the chase in Watertown. The pursuit went into a residential neighborhood, with the suspects throwing explosives at police.
A shootout erupted and ultimately one bomber -- later identified as Tamerlan Tsarnaev -- got out of the car. Police shot him, and his brother ran over him as he drove away, according to the law enforcement source, who spoke on condition of anonymity.
Richard H. Donohue Jr., 33, a three-year veteran of the transit system police force, was shot and wounded in the incident and taken to a hospital, a transit police spokesman said Friday. The officer's condition was not immediately known.
Another 15 police officers were treated for minor injuries sustained during the explosions and shootout, Jennifer Kovalich, a spokeswoman for St. Elizabeth's Medical Center, said.
Police believe the brothers are the same men pictured in images released Thursday by the FBI as suspects in the marathon bombing that killed three people and wounded dozens on Monday.
At least 58 people remained hospitalized, including three in critical condition, according to a CNN count.
The men are shown in the images walking together near the marathon finish line.