Franklin Lopez-Guardado, a 19-year-old resident of Richmond, California, was shot multiple times on February 6, 2014, around 4:30 p.m. on Dover Avenue in San Pablo. He was airlifted to John Muir Medical Center in Walnut Creek but died of his injuries. His death was reported as the first homicide in San Pablo since 2012.

Investigators say the shooting grew out of a dispute over a marijuana transaction. Two men were arrested in the days after the killing: Hector Paul Nava-Martinez, 20, of San Pablo, and Richard Contreras Barajas, 24, of Richmond; both were charged with murder by Contra Costa County prosecutors. A third man, Guillermo Memo Alexis Alvarez, 19, of San Pablo, is named on an arrest warrant and is being sought in connection with the case.

What information can anyone share about Lopez-Guardado, his movements that afternoon, or contacts who might help clarify the sequence of events?