It's been almost a year since the San Francisco Police Department said that they knew who was responsible for an infamous Hayes Valley quadruple homicide, but were unable to pull together enough of a case to make an arrest. But now police are saying they have a new lead that might bring the killer to justice, especially if they can gin up additional reward money for witnesses.

It was Friday, January 9 of 2015 when shots fired from a Hertz rental car struck Yalani Chinyamurindi, 19, of San Francisco; Harith Atchan, 21, of San Francisco; David Saucier, 20, of Antioch; and 22-year-old Manuel O’Neal as they sat in a 2005 Honda Civic near Page and Laguna Streets. All four died at the scene.

The suspect vehicle was traced to a Walnut Creek rental car agency, and though the car's renters were questioned after a dramatic chase, no one was arrested for the homicides. By April of last year, SFPD had started posting fliers in the area of the slayings, begging for public assistance in the investigation.

"Police believe they know who the killers are," ABC 7 reported at the time. "The are members of a Western Addition gang who may have ambushed the victims because they were on their turf," but no arrests have been made because police "have no witnesses."

"That's all we're missing at this point," SFPD Homicide Lieutenant Tony Chaplin said at the time. "We, like I said, have a lot of physical evidence. We just need someone to come forward and let us know what they saw that night."

It's unclear if a witness finally came forward, or what (and a call to SFPD wasn't returned to publication time), but it appears that there has been some recent movement in the case: According to Hoodline, while speaking at Monday night's Hayes Valley Safety Meeting, SFPD Chief Greg Suhr said that “We have a very good lead and we’re waiting for another couple things to happen."

In addition, Suhr said, “Supervisor Breed is looking at advancing the reward to a greater amount," likely referring to the recent Supe-approved creation of a reward fund for the arrest and conviction of homicide suspects.

That same fund was met with skepticism by the mayor's office, which told the Ex that “There has never been a problem with paying rewards out or with issuing rewards in the past.” But SF's top cop is less cynical about the bounty, saying Monday that "We believe we can leverage that reward to perhaps expand upon the lead we already have."

And there's always the reward of simply doing the right thing. Therefore, if you have any information on the case, please call SFPD's anonymous tip line at 415-575-4444 or send a tip by text message to TIP411 with "SFPD" at the start of the message.

Previously: Four Men Killed In Hayes Valley Shooting
Rental Car Used In Hayes Valley Drive-By Traced To Walnut Creek
SFPD Says They Know Who's Behind Hayes Valley's Quadruple Homicide, But They Still Need Witnesses