Kevin Pacheco, 36, surrendered to authorities after police cut power to the Richard Street home where he was holed up.
NBC 10 reported that police were actively working to get a warrant to search Pacheco's home, where they said he had "serious firepower".
Police told NBC 10 that Pacheco is facing charges, but that he's undergoing a medical evaluation.
A cousin of Pacheco told NBC 10 that Pacheco had depression issues for years following the death of his mother.
At one point during negotiations, police told NBC 10 Pacheco had asked for his medication.
Dartmouth police told NBC 10 they received an alert at about 11 a.m. for a man who made threats of violence against people at the Roger Williams University campuses in Bristol and Providence.
School officials said a former law school student had sent a threatening email Tuesday morning to some faculty and administrators and it raised concerns. School officials notified Bristol police who then called Dartmouth police.
Nearby residents were not evacuated but received a call from police saying something was going on in their neighborhood and to stay inside.
"They knocked on my mother's door and told her not to leave the house if she didn't have to. That was it," said one neighbor.
State and local police as well as a SWAT team were called to the scene. A state police helicopter was also at the scene.
New Bedford police also assisted.