Calvin Riley, a college baseball player at San Joaquin Delta College in California, was shot and killed Saturday in San Francisco while playing "Pokemon Go."

He was 20.

Sgt. Robert Jansing of the U.S. Park Police told Matt Hamilton of the Los Angeles Times that Riley was shot at 10 p.m. ET by an unknown gunman. He is believed to be the only victim, and officers are still investigating what led to the shooting.

"There doesn't appear to be any outstanding motive right now," said Jansing, who said Riley was not robbed in the attack.

Gabriel Antonio Morales, Riley's cousin, has set up a GoFundMe page that has raised over $36,000 since being set up Sunday, which will help pay for funeral costs.

"I know you moved [to California] to pursue your dreams of one day making it to the league and you had all the mechanics, talent and dedication to make your dreams a reality," Morales wrote. "But all that was taken by a coward who wanted to shoot up a Pokestop. I wish I got to talk to you one more time. I would've told you how much I loved you and missed you. How bad I look forward to seeing you again."

Riley, who grew up in Massachusetts, graduated in 2015 from Junipero Serra High School in San Mateo, California. He was a pitcher at San Joaquin Delta, a community college that has produced seven MLB draft picks since 2010.

Police have not determined whether Riley's murder was related to Pokemon Go, the GPS-based mobile game that has soared to prominence since debuting in July.