Ramos was killed in the early morning of her 28th birthday, on July 19th, while crossing Vaughn street near Glenoaks, in Pacoima.
Witnesses described seeing a white four-door vehicle, but had no further information.
Stumped officers said they've run out of leads and pleaded for anyone with information to come forward.
"If you are the driver we know that it was very dark, very sudden and an accident," said LAPD officer Eric Obrecht. "The family is grieving and wanting answers and we would like to know what happened so we can close our investigation."
Anyone with information is urged to call the LAPD at their anonymous hotline: 1-877-LAPD-24-7.