A person was shot and killed on Belmont Street in Brockton late Tuesday afternoon, said the office of Plymouth District Attorney Timothy J. Cruz. A spokesman for the district attorney’s office said the call came in to Brockton police just after 4 p.m. Authorities were not releasing the victim’s identity Tuesday night because they were trying to reach the family. The district attorney’s office did not release any other information about the incident, including the circumstances leading to the shooting or a description of the suspect. Brockton police said late Tuesday night that they could not confirm the shooting.