ARLINGTON, Texas (AP) — Police say a 17-year-old has been arrested on a murder warrant after fatally shooting a schoolmate on the campus of an Arlington, Texas, high school.

The slain student was identified as 18-year-old Etavian Barnes by the Tarrant County Medical Examiner’s Office.

Barnes was found unresponsive with multiple gunshot wounds Wednesday afternoon outside portable buildings on the campus of Bowie High School, according to Arlington Police Chief Al Jones.

No other injuries were reported.

The suspect, who was also a student at the school, was arrested a short time later near the campus, according to Jones, who said the two apparently knew each other.

“We’re still early on in our investigation, our detectives are working to determine a motive,” Jones said.

Jones said the shooting was reported about 2:50 p.m., shortly before classes were scheduled to be dismissed, and the school was placed on lockdown for about two hours before students were allowed to leave.

Arlington Independent School District Superintendent Matt Smith said classes at the school are canceled for Thursday.

“Honestly, I’m at a loss for words by this tragedy,” Smith said. “Schools are supposed to be a place of learning and growth” but that was interrupted by what he called “senseless violence.”

Smith said counselors will be available to students and staff when classes resume.