BOSTON – A man arrested three days after the shooting deaths of four people, including a toddler, was questioned the night of the killings, but was released because authorities lacked the evidence to immediately detain him, police said Saturday.

Kimani Washington, 35, of Boston was arrested on weapons charges Friday in Manchester, N.H., where he’s being held until his expected arraignment Monday on fugitive from justice charges.

Washington has not been charged with murder. At a news conference Saturday, Boston Police Commissioner Edward Davis said it was too early to comment on whether there were other suspects, and the investigation was continuing

Boston Mayor Thomas Menino said the arrest should serve as a warning to those who would harm others. “Our officers will not rest until you are hunted down, captured and locked up,” he said.

It was unclear Saturday if Washington had an attorney.

Five people were found shot early Tuesday on Woolson Street in one of the deadliest shootings in Boston in years.

Killed were 2-year-old Amani Smith; his mother, 21-year-old Eyanna Flonory; her boyfriend, 21-year-old Simba Martin; and 22-year-old Levaughn Washum-Garrison. Relatives say Amani died in his mother’s arms. The fifth victim, 32-year-old Marcus Hurd, was hospitalized Saturday in critical condition.

A spokesman for the Flonory family, Till Freeman, said Saturday that they “are grateful and thankful for the arrest, but, once again, nothing will take away the pain that our families are going through.”

Police first spoke to Washington about two hours after the shootings after Hurd gave police a description of a vehicle which he said a suspect had taken, Davis said. Washington agreed to speak to police after officers noticed Washington near a similar vehicle, he said.

At first, Washington denied any connection to the car, but later produced the key. But Davis said it wasn’t enough to arrest him. Davis said the vehicle, a rental car, was only similar to the one the victim described and it hadn’t been reported stolen.

“You have to understand no one was speaking at that scene at that time,” he said.

Davis said it took about 12 hours to link the vehicle to the crime scene. Police got a warrant to search a house where Washington had been living with relatives, then issued an arrest warrant for him after they found marijuana and two guns.

Davis declined to specify how they traced Washington to New Hampsire, except to say they acted partly on a tip.

Police spokeswoman Elaine Driscoll said tests, including ballistics testing, are being conducted to determine if the guns are linked to the killings.

Driscoll said Washington had a prior criminal record, but did not release details. On a Facebook page that a law enforcement source confirmed belonged to Washington, he refers to guns and violence.

In his most recent entry, dated Sept. 20, he wrote, “If u don’t spot the vic(tim) in the first 30 seconds that means ur IT. If u don’t hear the shots when the shells yell Sun that means ur HIT.”

In a Sept. 18 entry, he wrote, “Slip a click in the GLOCK (a type of handgun). Spit a bit (at) ya TOP. If not bigga 2 WALK then bigga in CHALK.”