Already facing multiple felony charges for armed robbery, a Salt Lake man has been indicted by a grand jury on charges of shooting at police.

Viliami Loumoli, 20, shot at two deputy U.S. Marshals last August as they chased the suspected gang member, according to the indictment returned Wednesday.

If convicted, Loumoli faces up to 20 years in federal prison for the assault charge, and up to life in prison on a related firearms charge.

"Law enforcement officers, including deputy marshals, put their lives at risk on a daily basis protecting us and working to keep our communities safe," U.S. Attorney for Utah Brett L. Tolman said in a prepared statement. "Assaults on police officers are something we are not going to tolerate."

Earlier this month, Loumoli and three others were indicted in a string of armed robberies around the Salt Lake Valley.