Boy, 15, Accused of Using Long Gun in Deadly Arlington Lamar HS ...

A 15-year-old boy is accused of using a long gun in a shooting Monday morning that killed a classmate and wounded another outside Arlington's Lamar High School, his defense attorney says.

The Tarrant County Medical Examiner's Office and family members of 16-year-old Ja'Shawn Poirier identified him as the victim in Monday's shooting outside the high school. The ME said Poirier had been shot in the head and chest with a shotgun.

The unnamed teen faces a capital murder charge in Poirier's death along with additional charges possible pending the outcome of the investigation, Arlington Police Chief Al Jones said Monday. The suspect's name has not been made public because he is a minor.

The teen was ordered to remain in detention on Tuesday after a hearing in state District Judge Alex Kim’s court, his defense team said. He will have another detention hearing every 10 days, as required by law.

The teen is being represented by defense attorney Lisa Herrick, a partner at Varghese Summersett. In a statement, the firm described Herrick as an expert in juvenile law and complex criminal cases involving minors and young adults.

“I had the opportunity to meet with this child first thing this morning,” Herrick said in a statement Tuesday. “He has never been involved in the juvenile justice system and is understandably emotional. This is a truly tragic case, but one in which we ask you to reserve judgment until we are able to reveal all of the facts and circumstances.”

Herrick is certified in juvenile law by the Texas Board of Legal Specialization and is one of only two attorneys in Tarrant County and 70 in the state who hold the designation, the law firm said.

The shooting began at about 6:55 a.m., before many students arrived for the first day back to classes after the spring break, according to police and school district officials.

Jones said Monday that in addition to the boy who was killed, a juvenile girl was also treated after being “grazed" in the shooting. Jones declined to give their ages or grades.

Arlington Police said they're still investigating a motive for the shooting and how the teen got the gun, which they confirmed to NBC 5 on Tuesday afternoon was a shotgun. Police also confirmed shotgun shells were found in the suspect's backpack.

A juvenile convicted of capital murder would face a maximum of 40 years in prison, according to the Texas Juvenile Justice Department.