denise chiffon berry , 44 , was driving in hawthorne , california with her unidentified 12-year-old son on wednesday .
around 12:30 pm , her son saw a man riding in a cadillac with his feet handing out the window and the two laughed at the scene .
when the cadillac began following their vehicle , ms berry pulled over to ask a police officer for help .
that 's when raymond washington , who was in the front passenger seat , got out of the cadillac and started shooting at ms berry and her son .
ms berry died at her scene while her son survived ; washington was shot dead by the police officer helping the mother and son .
washington , 38 , was a father-of-two and had a previous felony conviction .