EAST PALO ALTO (KPIX 5) — The mother of an East Palo Alto shooting victim is pleading for potential witnesses in her son’s slaying to come forward with information.

“I want to beg them to come forward and speak up,” said Veronica Sandoval, whose son Lalo was shot and killed last year.

On the one year anniversary of the fatal shooting, Sandoval marched with more than 100 people from St. Francis of Assisi Church to the East Palo Alto Police Department to raise awareness of the unsolved case and keep up pressure on detectives and elected officials.

Investigators say the murder took place in the early morning hours of Oct. 14, 2018 at A-1 Towing Services on Pulgas Avenue. An argument escalated to a fistfight and during the melee, one of the men was cornered against a fence. The man pulled out a gun and began shooting, killing Lalo Sandoval and Mario Mendez and injuring two others.

Lalo Sandoval (left) and Mario Mendez (right)

Detectives say 20 to 30 people attended the party and many of them likely knew the gunman, but they have not been forthcoming with information.

Police Commander Mike Stasko says the case is missing a key component: a strong witness.

“So now’s the time to look inside yourself and say, ‘Hey, come forward and stand up,’ and you will get the justice you’re looking for,” said Stasko to the demonstrators gathered outside the police department.

San Mateo County District Attorney Steve Wagstaffe says there are state and county programs in place that have protected and relocated “dozens” of witnesses over the years.

“If people come forward, then I predict 100% we will solve it. If people stay silent, then we may be exactly where we’ve been for the last 12 months,” said Wagstaffe.

Margaret Petros, executive director of Mothers Against Murder and the organizer of Sunday’s march, says the witnesses know many of the victim’s relatives and are carrying a heavy emotional burden by not coming forward to ease the families’ pain.

“Their lives have changed. A part of them has been murdered. And if you are in a position to change that, to comfort that mother, I cannot imagine not doing it,” said Petros.

By the end of the march, demonstrators tied white balloons on the railing of the police department to remind detectives and the public to stay vigilant. Meanwhile, Veronica had a message for the gunman, who has not been seen in the area for months.

“For once in your life, do the right thing. You were a grown up man to use the gun. And you will have to pay for what you did, sooner or later,” said Sandoval. “He can run, but he can’t hide.”