WOODLAND HILLS (CBSLA) — Three weeks after a former student opened fire at a Palmdale high school, the sole teen shot during the incident announced he has filed a claim against the school district ahead of a possible lawsuit against the agency and the alleged shooter.

“I was just, like, really shocked to see that a gun was pointed at me and feeling the pain after,” 15-year-old Robert Ruiz Dominguez told reporters at a Thursday press conference.

The Highland High School student was still in an arm cast when he spoke to reporters.

Robert was allegedly shot in the arm with a rifle by a 14-year-old suspect on the morning of May 11.

The alleged shooter, a former student at the high school, also shot at Robert’s 17-year-old sister Christina during the incident. She was not injured.

“I was just scared for my sister because I saw the gun being pointed at her,” said Robert.

On the morning May 11, the former student allegedly entered the school with what Los Angeles County Sheriff Jim McDonnell identified as an SKS rifle.

“This boy came out of the bathroom. He had an AK-47, as I understand it, and the bathroom is very close to where [the siblings] were sitting doing homework,” said Robert’s attorney Bradley Gage. “He just opened fire.” He maintains it was a random shooting.

After the incident, police said they had no motive, and it was unclear if the alleged shooter knew the siblings.

The suspect was arrested at a nearby Vons after the boy called his father to tell him he had fired a gun into the air.

Gage claims the school resource officer was scheduled to arrive at the school at 9 a.m., about two hours before the shooting happened. He said this was a failure on the part of the school to keep their students safe, and said the security officers were not properly trained.

“The schools have an obligation to protect our students,” said Gage. “We had a situation that was a perfect storm.”

Gage said the school didn’t have a safety plan or screening devices for the campus.

Robert, who plays the violin and the trumpet, said he doesn’t have full use of his right arm or fingers. He has metal plate and nine screws in his arm, as well as a giant incision down the length of his forearm, a gruesome photo of which Gage showed reporters.

Incision on Robert Ruiz Domingues’s arm (SOURCE: Bradley Gage)

Older sister Maria said her siblings have emotional scars, as well.

“He keeps remembering everything that happened,” said Maria. “He can’t be around noisy people. He can’t be around noisy places. He can’t hear loud sounds, he gets startled — same with my sister.

Christina graduated from Highland High Wednesday, but Robert still has a few years left, and despite his ordeal, he said doesn’t want to leave the school.

“I don’t even, like, feel like going to any other school ’cause it happened at one school, and it could happen at another,” Robert said.

The Antelope Valley Union High School District told CBS2 News they continue to support Robert and his family, and that they are working with law enforcement to fortify safety protocols at all of their schools.

They added they have a school deputy on campus every day and perform safety drills throughout the year.

AVUHSD released the following statement Thursday:

“We are incredibly thankful that no lives were lost during the recent incident at Highland High School and that our injured student is recovering, that said, we acknowledge that the child and his family have been through a traumatic experience and we have offered them our support since the day of the incident and will continue to do so. We also continue to work with our law enforcement partners to fortify our safety protocols across all our schools.”

This story has been updated with the district statement.