Ten people were killed and 10 wounded in a shooting Friday morning at a high school south of Houston, authorities said. The shooting at Santa Fe High School was the nation’s deadliest such attack since the massacre in Florida that gave rise to a campaign by teens for gun control.

Nine students and a teacher were killed in the Friday’s shooting, law enforcement sources told CBS News senior investigative producer Pat Milton. Another 10 people were wounded, Texas Gov. Greg Abbott said at an afternoon news conference.

Officials began identifying those killed in the attack Friday afternoon, including Ann Perkins, a substitute teacher at the school, and Sabika Sheikh, a Pakistani exchange student.

The suspect in custody was identified as 17-year-old Dimitrios Pagourtzis, Galveston County Sheriff Henry Trochesset said in a statement. He was being held without bond on a charge of capital murder. Harris County Sheriff Ed Gonzalez said the suspect was believed to be a student at the school. CBS News.