Alameda County’s top lawyer on Monday, Nov. 9, sent Immigration and Customs Enforcement a cease-and-desist letter demanding that agents stop using Santa Rita Jail and its parking lot for civil immigration enforcement, The Oaklandside reported and KQED reported.

Why it matters: The letter says sheriff’s officials have told agents to leave and that “ICE personnel have repeatedly ignored those instructions.” Supervisor Nikki Fortunato Bas said that if the warnings are ignored, “it would likely be legal action.”

According to the county, ICE agents on Nov. 1 chased someone from the parking lot into the jail lobby and detained them there. On Nov. 8, the county said, two agents got into a physical confrontation with members of the public in the lobby, creating “potentially dangerous and unpredictable circumstances carrying an unacceptable risk of confusion and physical harm.” Interim Counsel Andrea Weddle addressed the letter to Julio Hernandez, acting director of ICE’s San Francisco office, The Oaklandside reported.

The county’s ICE-free zones policy, adopted in January, prohibits using county property as a staging ground for civil immigration enforcement without a judicial warrant. Advocates said the sheriff’s office had locked the jail lobby as of Friday night; the sheriff’s office and ICE did not respond to the news organizations’ requests for comment. Related: the sheriff’s earlier account of ICE activity outside the jail.