AUSTIN, Texas (AP) — Police made a second arrest Monday in a weekend shooting that killed a man and left more than a dozen more people wounded after gunfire rang out on in a busy, downtown Austin entertainment district.

Officers arrested a 17-year-old boy at Harker Heights High School in Harker Heights, according to statements from Austin police and the Killeen Independent School District. He is facing a charge of aggravated assault.

Austin police are working closely with the Killeen Independent School District and its police department in the investigation, according to a statement from the district.

A spokesman for Killeen school police confirmed the arrest of the 17-year-old and referred further questions to the school district about 70 miles north of Austin. The school district referred questions to Austin police, who did not immediately respond to a request for comment.

Austin police announced a prior arrest Saturday, hours after the early-morning shooting. Interim Police Chief Joseph Chacon has said investigators believe the violence started as a dispute between two parties. Chacon declined to disclose details such as whether detectives believe both suspects fired shots, citing the ongoing investigation.