Los Angeles County Undersheriff William T. Stonich, the department's second highest-ranking official, announced his retirement Wednesday.
Stonich, 61, is Sheriff Lee Baca's closest confidant and the man he relies on day to day to run the massive agency.
"I put forward the mission and direction, but he is the one responsible for implementing my vision," said Baca, who called Stonich's departure a loss for the county. "He personifies my view of the department. No job is too big, no responsibility too small."
Stonich, a Newport Beach resident, said that after 35 years with the department he would miss the job but looked forward to retiring Jan. 18.
"I'll continue to live vicariously through my son and my son-in-law, who are both deputy sheriffs," he said.
A former high school football and swim coach, Stonich joined the Santa Ana Police Department after serving in the Army. In 1969, he became a sheriff's deputy.
Stonich helped run Baca's 1998 campaign for sheriff against longtime incumbent Sherman Block and sent a letter to deputies asking them to break ranks with their boss and support Baca's challenge.
Baca said that at tough points during that campaign, Stonich kept him going.
That year, Baca promoted Stonich to assistant sheriff, and two years later to undersheriff.
"He is a great cop and leader, but he also believes in helping others," Baca said.
He said Stonich was instrumental in starting the charity run by law enforcement officers for disabled foster children.
Stonich's replacement will come from the ranks of veteran managers, Baca said.