Police said Ramos, 27, who lived in Emeryville, was shot at the mural site under the Interstate Highway 580 overpass on West Street between 35th and 36th streets at about 10:30 a.m. last Tuesday and was pronounced dead at a hospital a short time later.
VIDEO: Witness describes moments before artist murdered in West Oakland
Police said a male suspect fled on foot after the shooting and is still at large.
Police said today that they're asking the public to help identify and locate a person of interest who is described as a black man in his 20s who's about 6 feet tall with a thin build and a dark complexion.
Oakland police have released a photo of the person of interest that they said was taken by a video surveillance camera near the scene of the shooting.
Ramos was a muralist with Art Esteem, the literacy and art arm of Attitudinal Healing Connection, a West Oakland group that seeks to stop violence by inspiring people with art and education.
VIDEO: Friends mourn loss of artist shot while working on West Oakland mural
More than 100 people attended a vigil for him at the shooting scene last Wednesday morning.
Police said Crime Stoppers of Oakland has offered a reward of up to $10,000 for information leading to an arrest in the case.
Oakland police said people who have information about the fatal shooting should call the department's homicide section at (510) 238-3821 or Crime Stoppers of Oakland at (510) 777-8572.