It comes just days after a fan suffered a concussion and broken arm following a beating at Sunday's 49ers-Colts game at Candlestick Park.
Stadium security and fan behavior also came under scrutiny when another Dodgers-Giants matchup saw a Northern California paramedic severely beaten. Brian Stow, a Giants fan, suffered a traumatic brain injury after a beating by two men dressed in Dodgers gear following the March 31, 2011, home opener between the teams.
Stow's family says he's still enduring physical pain and memory loss from a severe brain injury.
The two suspects in his attack are waiting to go to trial.
The Giants are holding a fundraiser for Stow. The team will donate $10 from each ticket sold in certain sections of AT&T Park at Tuesday, Thursday and Sunday's games to a fund setup for Stow.
Unfortunately, violence leading to serious injuries at local sporting events is not uncommon.
Earlier this year there was a violent scuffle inside AT&T Park during a Giants-A's game, while back in 2003 a Southern California Giants fan was shot and killed in the parking lot at Dodgers Stadium during the 8th inning.
In October of last year, an Elk Grove man was stabbed during an argument between fans at a 49ers game. Two suspects were arrested.
And back in August of 2011, two men were shot in the parking lot outside Candlestick Park before a 49ers-Raiders preseason game. Another fan was severely beaten inside a stadium restroom.
A friend of Stow's hopes Wednesday night's murder wasn't payback for his attack.
"I hope and I wish that people would learn from the tragedy that happened to Bryan and that everyone's disgusted by it," said Stow's friend, Chris Boardman. "Dodgers fans, Giants fans, I was hoping that everyone would be completely ashamed of those guys."
San Francisco Mayor Ed Lee says we've got to do better to prevent violence associated with sporting events.
"It's horrible," he said. "Any time people commit to violence, whatever they're doing, obviously we abhor that."
The San Francisco Police Department will have a beefed up presence at the ballpark as decoy Dodgers fans.
"There's no place in San Francisco for that type of violence," Sgt. Danielle Newman said. "The rivalry needs to stay out on the ball field; not in the stands, and not on the streets."
The city and the Giants plan to work together on violence prevention.