As his first official act, new San Francisco police Chief George Gascon declared war on the Tenderloin drug trade.
In August, a 20-day operation resulted in more than 300 arrests of suspected dealers. A recent month-long crackdown around schools in the Tenderloin netted more than 50 arrests.
Police say prosecutors are charging most of those in custody and they are getting higher bails and stiffer sentences.
For example, parolee Keith Straub with repeated arrests for dealing recently got six years in prison and suspected dealer Tom Kaina on probation for selling near a school cannot make a $200,000 bail.
"The majority of our narcotics dealers are from the East Bay -- Alameda County, Contra Costa County, especially," San Francisco police Sgt. Mark Obrochta said.
Obrochta works in the Tenderloin police station.
"We follow the narcotics back to Oakland and we usually do search warrants in Oakland with the assistance of the Oakland Police Department," he said.
Police say Oakland has long been the epicenter for drug distribution in Northern California. The city's new police chief can personally vouch for that.
"When I was chief at Long Beach, we did a case that left at the border of Mexico and came directly up the 5 freeway and stopped right at this area and then dispersed in this area," Chief Anthony Batts said.
Batts and Gascon say they are creating the framework of a regional partnership to fight the drug war.
"He and I will be connecting and working together along with other chiefs in the region," Batts said.
"The people who are committing crimes here are also committing crimes in their home town, so rather than work independent from one another, we need to identify who are the more troubling people and how do we work collectively so we protect every community in the area," Gascon said.
Batts says they had a good working relationship when he was chief in Long Beach and Gascon was the assistant chief in Los Angeles.
That should help their new partnership in the Bay Area.