Law enforcement personnel guard the scene of a suspected shooting near Robb Elementary School in Uvalde, Texas, May 24, 2022. Photo: Marco Bello/Reuters

Law enforcement shared this photo of 18-year-old Salvador Ramos, a student at Uvalde High School, who has been identified as the alleged gunman in the Robb Elementary School shooting on May 24, 2022, in Uvalde, Texas. Photo: ABC News

The 18-year-old suspect, a student at Uvalde High School, is also dead, Governor Greg Abbott said.

Abbott said the suspect "shot and killed horrifically and incomprehensibly" more than a dozen students and a teacher.

The suspect also allegedly shot and killed his grandmother before entering the school and again opening fire.

The shooter was identified by law enforcement sources and the governor as Salvador Ramos. Authorities have recovered an AR-15-style rifle and numerous magazines, multiple law enforcement sources told ABC News.

"When parents drop their kids off at school, they have every expectation to know that they're going to be able to pick their child up when that school day ends. And there are families who are in mourning right now," Abbott said. "The state of Texas is in mourning with them for the reality that these parents are not going to be able to pick up their children."

Two responding police officers were among those injured, Abbott said. They are expected to survive, he said.

Uvalde Memorial Hospital had said 15 students were being treated in the hospital's emergency department in the wake of the incident. Two patients were transferred to San Antonio for treatment, while a third was pending transfer, the hospital said. A 45-year-old was also hospitalized after getting grazed by a bullet, the hospital said.

University Health in San Antonio said it had two patients from the shooting incident -- a 66-year-old woman and a 10-year-old girl -- both in critical condition.

Two adult victims of the shooting, both in critical condition, are also being treated at Brooke Army Medical Center in San Antonio, according to an Army official.

A number of the shooting victims are children of Customs and Border Patrol agents, law enforcement sources told ABC News.

The National Counterterrorism Operations Center believes there is "no known terrorism nexus" at this time, according to a law enforcement bulletin obtained by ABC News.