LEWISTON — Maine State Police and the Lewiston Police Department charged a 20-year-old Auburn man with murder in the Saturday shooting of an 18-year-old on River Street.

Abdikadir A. Nur was arrested by Auburn police about 9 p.m. Monday at his mother’s residence on Aspen Street in Auburn, according to a statement from state police late Tuesday afternoon. Nur was arrested on a state police warrant for violation of conditions of release.

The Maine Attorney General’s Office approved an arrest warrant for Nur on Tuesday afternoon for the additional charge of murder in the shooting of 18-year-old Hassan Hassan on River Street in Lewiston. He died at Central Maine Medical Center at 2:44 a.m. Sunday.

The murder charge is a result of an extensive investigation by the state police, Lewiston Police Department, Auburn Police Department, Portland Police Department, Maine Drug Enforcement Agency, U.S. Marshal’s Service, Federal Bureau of Investigation, and the Department of Homeland Security, according to the statement.

Nur had been out of jail on $10,000 bail since Sept. 30 after his arrest by Lewiston police on a charge of elevated aggravated assault in July stemming from a shooting in May, according to the news release.

He is being held at the Androscoggin County Jail.

Police previously charged Nur in the shooting of George Simmons on May 27 in the area of 147 Bartlett St. Police responded there about 5:10 p.m. and found Simmons had a single gunshot to the abdomen, police said.