STOCKTON (CBS13) — A 13-year-old Stockton boy is among four suspects arrested and charged with robbing and killing a 20-year-old man who had just finished working and was walking to his car.

The victim was an employee at a fast food restaurant who had dreams of becoming an officer with the California Highway Patrol.

Cassandra Valadez can’t help reading over and over the last text message she received from her boyfriend, Juan Dominguez, 20. It was sent a few hours before he was shot and killed.

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“He said ‘and I will let you know when I get home. Good night, sweet dreams and I love you,” she said.

Valadez and Dominguez met at Franklin High School. They dated for close to two years and even talked about getting married.

“Our relationship was probably the best one anyone could ever ask for. He treated me like a queen and he was never part of anything bad. He just cared about his family, his rights and having a future,” she said.

Stockton Police arrested and charged two boys, a 13-year-old and a 16-year-old, in Dominguez’s murder. They also arrested a 17-year-old female and a 19-year-old boy for being accessories. The teens were spotted by Sacramento County Sheriff’s deputies hours after the shooting driving the victim’s Honda Accord.

“The question that comes to everyone’s mind is why? We wouldn’t be having this discussion right now if those kids were where they were supposed to be that morning, and that is at home,” said Joe Silva with the Stockton Police Department.

Dominguez was gunned down in the parking lot of Panda Express where friends say he recently started working while he pursued a career with the CHP. He worked different shifts often staying later than his schedule to help clean the restaurant.

“He really was an amazing human being and all that. Like, it really hurts knowing that you’re never going to have that light anymore. They took it away,” said Austin Kenyon, victim’s friend.

Stockton Police say the investigation is still active. They believe they have all the suspects involved in the shooting and say there could be additional charges down the road.