Andy Lopez protesters blocked traffic on Highway101 in Santa Rosa

SANTA ROSA, Calif. -- A group of protesters gathered Saturday afternoon and blocked traffic on northbound U.S. Highway 101 in Santa Rosa to show their disapproval with the Sonoma County prosecutors' decision not to file criminal charges against a sheriff's deputy who fatally shot 13-year-old Andy Lopez in October. Around 5:17 p.m., officials said the protesters moved off of the freeway and marched back into downtown Santa Rosa.

The rally began peacefully around 1 p.m. in the vicinity of Old Courthouse Square in response to the decision announced Monday not to prosecute the deputy who shot and killed Lopez, who was carrying a toy gun.

Around 3:40 p.m., over 100 protesters began marching together down Third Street.

Pedestrians blocked traffic in the vicinity of Mendocino Avenue, Third and Fourth Streets, and D Streets, police said.

Around 4:30 p.m. a smaller group of the protesters marched up onto northbound Highway 101 at Third Street.

Vehicles on the highway came to a stop and protesters held up banners across the roadway and chanted.

Officers with the California Highway Patrol arrived and stopped traffic from getting close to the protesters.

The group of protesters then walked back down the ramp onto Third Street, where a standoff with police officers began.