Tens of thousands of inmates who should have been eligible for release from sheriff’s custody allegedly remain detained for days or even months because of immigration-related holds. Such is the claim made by the American Civil Liberties Union (ACLU) of Southern California, which is now filing a federal lawsuit against Los Angeles County Sheriff Lee Baca. The ACLU said it will file the federal lawsuit Friday challenging Sheriff Baca’s ability to detain arrestees solely on the basis of an immigration hold when they are eligible for bail or other forms of release. Plaintiff Duncan Roy — a British film director — said he was held in jail for nearly three months because of a hold filed by Immigration and Customs Enforcement, even though he tried multiple times to post bail. “The sheriff says, he’s on an ICE hold, and the ICE people say, well, he’s got to make bond,”