DUBLIN -- A 54-year-old Santa Rita Jail inmate committed suicide by hanging himself Saturday, officials say.

Dennis Jimenez had been in custody since March 11, when he was arrested in Oakland on driving under the influence, drug and theft charges, according to a statement from the Alameda County Sheriff's Office. He was due to be released Wednesday.

Jimenez was found alone in his cell, with a bed sheet fashioned into a noose. He was transported to Valley Care Hospital in Pleasanton, where he was pronounced dead.

Per protocol, sheriff's detectives from the Eden Township Substation and the coroner's office investigated the death, officials said.