Leon Brown, a close friend of Foster's, says Foster was a young man with a ready smile and bright future.
"This let me know that there's people out there that don't want to see young men doing great, they don't want to see young men that have something going for themselves be successful," Brown said.
Foster was shot and killed Wednesday night in the field behind San Leandro's Hillside School. The Alameda County Sheriff's Department say it appears Foster was involved in a game of dice with several others, when gunfire erupted.
"He was found on the school grounds, but again we don't want to assume for 100 percent that that is exactly where th crime occurred because he might have run to that spot," Sheriff's Department spokesperson J.D. Nelson said.
Foster was a red-shirt freshman on the Laney College football team this past season. He was a graduate of Oakland's McClymonds High School, where he also played football.
At Laney, his coach told ABC7 News, he would've been on the field today for spring conditioning with his teammates.
"It's felt to everybody here; Travion was a red-shirt linebacker, trying to do the right thing, transitioning from high school to college," John Beam said.
Classes were canceled at hillside elementary school Thursday to give investigators time to gather any evidence that might be in the field during daylight hours.
"We don't expect something like that to happen at school, and not at the night time; it's supposed to be closed, safe for the kids," parent Veronica Navarro said.
Foster's loss hits the Laney football team especially hard. Earlier this week they lost another player, David Moa, in a car accident in southern California.
"When you see you see young people try to do the right thing, making the sacrifices, going to school everyday, it's tough," Beam said.
District officials plan to re-open Hillside Elementary to students on Friday now that investigators have collected any evidence that might have been there.
Investigators say they do have leads in Foster's murder but so far have made no arrests.
Friends, family gather at school to mourn teen
There was a massive turnout Thursday night at the school for a vigil held to honor the teenager.
One man there said, "Now his baby sister has got to grow up without a big brother."
To friends and family of Trevion, none of this makes any sense. His mother, Tara Washington, said her son had no enemies.
"I know my son did not deserve what happened to him at all. He should still be with me. I should not have to bury my baby," said Washington.
Trevion's father, also named Trevion Foster, has his own theories as to what may have happened.
"He was gullible I think and they preyed on that because he was just a cool guy like that. He wasn't thinking that, 'I'm going to go over there and beat your money and then you're going to try to shoot.' He's not thinking like that," said Foster.
Trevion had big dreams for his football career. He wanted to follow in his god brother's footsteps. Derrick Hill played at Cal and then with the Oakland Raiders. Thursday night, he held a "player of the week" plaque Trevion received while a senior at McClymonds High.
"When you see somebody that you try to help mold their life, and try to get them on the right track and keep them on the right track, to see them doing that, and still bad things happen, it hurts," said Hill.
Family members are now holding out hope for justice. Trevion's mother had one plea. She said, "Whoever did this to my son please come forward."