A Tompkins County sheriff’s deputy’s unprompted decision to alert ICE to the presence of an undocumented immigrant in Lansing — an action likely not in violation of county “sanctuary” law but very much against its spirit — is deeply disturbing, and warrants significant review. It may already be too late to help the man in question, who now sits in a federal cell in Batavia. But Tompkins County can take steps to ensure this situation goes unrepeated, and to reassure the county’s undocumented residents that they are welcome here and should not fear local law enforcement. It is puzzling why the Sheriff’s Office did not have an internal policy outlining the protocol for situations involving federal immigration enforcement, especially considering that Tompkins County’s sanctuary law passed in 2017 and is potentially germane to that office’s functions. Though we are encouraged by Sheriff Derek Osborne’s work since the arrest to draft an internal policy mirroring county law — and we do note that Osborne only took office six weeks ago — there should be a review of why it took so long, and a precipitating incident such as this one, to spark change.