Los Angeles County Sheriff Lee Baca, who announced his pending retirement Tuesday, has had a complicated relationship with immigrants in his jurisdiction during his 15-year tenure. He’s the son of a Mexican-born immigrant mother who once lacked legal status. Yet he’s held a hard line on immigration enforcement that has made him a controversial figure among immigrant rights advocates. Baca was a staunch supporter of federal-local immigration enforcement partnerships like Se Communities, which has contributed to record deportations nationwide, only softening his stance in the last year or so. Baca, who is 71, announced Tuesday morning that he would not seek a fifth term. He did so on the heels of a scandal over inmate abuse in county jails, with federal criminal charges filed a month ago against 18 current and former deputies. Some of those deputies have been accused of attempting to obstruct an FBI investigation into the department.