Mehserle, 28, was convicted last month of involuntary manslaughter for the fatal shooting of Oscar Grant III at the Fruitvale BART station in Oakland on Jan. 1, 2009. His sentencing is scheduled for Nov. 5.
About 20 Mehserle supporters gathered between about noon and 4 p.m. in front of Dublin City Hall, located at 100 Civic Plaza, said Lt. Steve Brown. Six Dublin police officers were stationed at the scene for the event, Brown added.
Four counter-protestors briefly attended and took photos of Mehserle supporters. They told the rally participants they would post the images online, Brown said.
But the rally ended without confrontation and was "very peaceful," Brown said.
"The Mehserle supporters were very cooperative and did exactly what they said they were going to do," he said.
Organizers of the rally notified city officials of their plans before the rally, Brown said.
A July 19 Mehserle rally and counter-protest in Walnut Creek drew between 250 and 300 people with both sides accusing the other of racism and ignorance. The event ended peacefully with no arrests, injuries or property damages.