SAN FRANCISCO (AP) — A man serving a life sentence for fatally shooting seven people at a small Northern California vocational college has died in prison.

The California Department of Corrections and Rehabilitation said Wednesday that 50-year-old One Goh died at California State Prison-Sacramento on March 20. CDCR spokeswoman Vicky Waters said a cause of death hasn't been determined. She did not respond to requests for more details.

Goh was also convicted of injuring three people during the April 2012 shooting at the Christian-affiliated Oikos University in Oakland. Police said Goh was angry with school administrators for expelling him and refusing to refund his tuition.

Goh pleaded no contest to murder charges in 2017 after a judge declared him mentally competent to stand trial after previously finding him unfit in 2013 and 2015.