The man accused of shooting a fellow Muni passenger to death Monday night not only didn't know the victim, he had no interaction with him prior to the killing, police Chief Greg Suhr said Thursday.
Nikhom Thephakaysone, 30, allegedly shot San Francisco State University student Justin Valdez in the back for no apparent reason at the corner of Randolph and Bright streets on Monday night.
Thephakaysone, who reportedly isn't cooperating with investigators, boarded the M-Ocean View Muni train near SFSU at the same time as Valdez, about 9:40 p.m.
"The suspect stood 5 to 8 feet away from Mr. Valdez and there was no interaction" between them, Suhr said.
Security video on the train allegedly showed Thephakaysone taking out and putting away a .45-caliber handgun several times. About 90 minutes before that train ride, according to reports that emerged after the killing, Thephakaysone had pointed a gun randomly at people on two separate occasions.
About 9:50 p.m. that night, Valdez was shot right after disembarking the train. Thephakaysone left his gun at the crime scene and fled, police said.
An investigation led police to the 200 block of Lobos Street, where Thephakaysone lives with his mother and stepfather, Suhr said. The home is about three blocks from the crime scene.
Upon his arrest, Thephakaysone was reportedly carrying $20,000 in cash. In the home, police found a cache of weapons that included an assault rifle, a second firearm, two assault or survival knives and a survival pack with medical supplies and other items.
"We have no idea why he did what he did," Suhr said.
There was no indication that Thephakaysone is mentally ill, the police chief added, nor was there evidence that he planned to harm more people.
Loved ones of Valdez are equally stunned by the killing. Valdez was described as a persistently positive person who was a staunch advocate for the environment. He graduated two years ago from Garden Grove High School in Southern California, where he was a finalist for the school's most prestigious award given to students, principal Steve Osborne said.
Valdez's sister, Jessica Labidi and her husband Nazar Labidi attended Thursday's press conference but did not speak publicly. They have set up a fund to pay for the transport of Valdez's body to Southern California. The Justin Valdez Memorial Fund can be accessed at Giveforward.com.