Boston police arrested a man with a criminal past on Saturday night who they believe was responsible for leaving an explosive device near a police cruiser in South Boston last week that almost blew up the vehicle.

Asim Kieta, 42, was taken into custody without incident in Charlestown around 9:30 p.m. Saturday following a lengthy investigation, police announced Sunday at a morning press conference.

“I’m thrilled we got him,’’ said Police Commissioner William B. Evans. “Obviously, we were very concerned with all of our police officers being out there. Unfortunately, over the last two years, police officers have come under attack.’’

On Friday morning, an explosive device fueled by a propane tank detonated near a cruiser parked outside of a district station on West Broadway. A nearby officer noticed smoke and fire coming from the device, and police quickly moved the cruiser shortly before the explosion, which sent pieces of metal into the street.

Evans said the investigation continues and a motive had not been established. He said investigators believe that Kieta, who is homeless but previously lived in Dorchester, acted alone, and there was no indication Sunday of a larger plot.

“Looking back, he’s had some encounters with police officers, so I don’t know if it was payback or not,’’ Evans said.

Police quickly narrowed in on Kieta, who has a “lengthy criminal past,’’ Evans said, using police and witness accounts and surveillance footage of the suspect and his vehicle.

Video allegedly showed Kieta walking away from a 2014 Toyota Camry that was parked near the explosion, carrying what appeared to be a grocery bag, police said. “We have video that shows him quickly looking over his shoulder, going back to that vehicle, and driving away,’’ Evans said.

Police are working with the FBI to piece together the device, which was blown apart “pretty well,’’ Evans said.

People in the area reported hearing two explosions minutes apart and seeing flames.

Evans said there may have been fireworks on top of the propane tank, which would account for the two booms.

Two officers were treated for minor injuries as a result of the incident, officials said, and the marked police vehicle sustained minor damage.

Officials released a blurry image of the suspect and a description of the vehicle to the public on Friday. Police were able to establish the plate number of the vehicle, which was registered in Kieta’s name, and located the suspect driving on Rutherford Avenue in Charlestown on Saturday. The Toyota is in police custody; as of Sunday, police were awaiting a search warrant.

“I’m glad we got this dangerous guy off the street before, obviously, he takes any more of his hatred out on police officers,’’ Evans said.

Kieta faces multiple charges, including possession of an explosive device, assault with intent to murder, assault and battery with a dangerous weapon, assault and battery of a police officer, and arson.

He is scheduled to be arraigned Monday in South Boston District Court.

Steve Annear can be reached at steve.annear@globe.com. Laura Crimaldi of the Globe staff contributed to this report.