Justin Valdez, 20, of Garden Grove, was a sophomore at San Francisco State University. Police say he was gunned down on Monday night in what appears to be a random attack after he got off a Muni train.
A camera onboard captured video of the suspect, who is now in custody. The motive for the shooting remains under investigation.
Valdez graduated from Garden Grove High School. Friends say he was kind to everyone and always set an example.
"He was always that type of person. Everything he did he had to work hard for. He was never given anything. He always had to prove himself," said friend Dilon Papa.
Valdez played water polo and was captain of the swim team. Coach Eric Henniger says he was an incredibly hard worker.
"He took that hard work and his commitment to the team over a few years and he ended up being one of the best swimmers on the team and in the league," said Henniger.
But perhaps his biggest impact on the school was as president of the Environmental Club. He pushed for a recycling program on campus and started "Lights Out Wednesdays."
"The idea was to cut down on the amount of electricity used during the day, measure the amount of electricity and then determine how much we're able to save," said Garden Grove High School Principal Steve Osborne.
In memory of Valdez, the school plans to restart the program. Friends say conserving energy and recycling are the best ways to honor the young man who made a lasting impact on their lives.
"I knew him really close, so it hit me hard, but I know he would want us to change our individual worlds, to carry on his legacy, to carry on the things that he didn't get to do," said friend Conrad Smith.
The school plans to hold a candlelight vigil on the pool deck at 7 p.m. on Friday and Sunday.