An anonymous tip helped detectives identify an 18-year-old as a suspect in an alleged assault that caused “significant injuries” to another teenager in downtown Colorado Springs on March 15, according to city police.

Detectives obtained an arrest warrant Thursday for Elijah Benjamin Valdez of Pueblo, who already was in custody at the Pueblo County jail on attempted homicide charges, according to court records.

In El Paso County, he faces charges of second-degree assault, possession of a weapon by a previous offender, menacing and violating a protection order.

The alleged assault occurred about 2:35 a.m. in the 400 block of North Tejon Street and required the victim, a 19-year-old who lives in Colorado Springs, to receive “immediate medical treatment,” police said.

Valdez is scheduled to appear in an El Paso County courtroom for his first appearance in the assault case on May 11.

In Pueblo, Valdez faces two attempted murder charges with extreme indifference and possession of a weapon by a previous juvenile offender. He has yet to post his $350,000 cash only bond and is expected to appear in a Pueblo County courtroom on June 11, court records show.

The investigation into the alleged assault in Colorado Springs remains active and anyone with information can reach police at 719-444-7000 or remain anonymous on the Crime Stoppers tip line at 719-634-7867 or 1-800-222-8477.