SAN FRANCISCO (CBS SF) -- Police have arrested a man suspected in the fatal shooting of a San Francisco State University student as he stepped off a Municipal Railway light-rail vehicle.
San Francisco Police said 30-year-old Nikhom Thephakaysone of San Francisco, was taken into custody without incident Tuesday outside of his residence in the Oceanview District.
He has been charged with homicide and remained in custody, according to a police statement.
The arrest follows the release of video footage of the shooting suspect captured by a surveillance camera on the Muni train.
The victim, Justin Valdez, 20, a San Francisco resident, was originally from Garden Grove in Southern California.
He was shot around 9:50 p.m. as he left an eastbound Muni light-rail vehicle near Randolph and Bright streets, according to police. The M-Ocean View line stops at that corner.
SFSU officials said Valdez was a sophomore who had started in the fall of 2012 and had not yet declared a major.
University president Les Wong said in a statement Wednesday, "This is truly a tragedy for Justin's friends and family, and for the entire University community. I have reached out to Justin's family to offer our heartfelt concern, and to assure them that we stand ready to offer support and assistance at this difficult time."
Grief counseling was available on campus for students, faculty and staff.
Valdez had attended Garden Grove High School and lived with his uncle, his high school principal Steve Osborne said.
Osborne recalled a "passionate and persistent" student who was the president of the school's environmental club and a top competitor in the Garden Grove High aquatics program.
While Valdez was a student, he would talk with Osborne frequently to see about changes to the school's recycling program, the principal said.
He also pushed tirelessly to establish a "Lights Out Wednesday" program to cut the school's carbon footprint, according to the principal.
Vigils will be held in Valdez's honor at the high school's pool deck on Friday and Sunday, and there will be a "Lights Out for Justin Day" in the coming days, Osborne said.
"It's been devastating for teachers who knew him," Osborne said.
According to Valdez's Facebook page, he was a member of the SFSU Men's Club Water Polo team.
The motive for the shooting remains under investigation. Police said the suspect and Valdez did not appear to know each other.
Anyone with information about the case is asked to call the Police Department's homicide detail at (415) 553-1145. People can also call anonymously to (415) 575-4444 or send a tip by text message to TIP411 with "SFPD" in the message.
(Copyright 2013 by CBS San Francisco and Bay City News Service. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)
for more features.