A welcome departure at the Sheriff’s Dept.

Undersheriff Paul Tanaka, one of the most controversial figures in the Los Angeles County Sheriff’s Department, is stepping down. That’s welcome news.

Tanaka has been accused by current and retired sheriff’s deputies of condoning and at times encouraging misconduct and abuse in the department. They say he created a climate that prized aggression and loyalty over good policing. A county commission looking into violence in the county jails concluded last year that Tanaka had tried to undermine the credibility of internal affairs investigators. And The Times has reported that a federal grand jury heard testimony about the undersheriff’s role in allegedly hiding an informant from the FBI.

Few who have followed the upheaval in Sheriff Lee Baca’s department over the last couple of years can have forgotten Tanaka’s infamous statement to deputies encouraging them to work in the “gray area” — language Tanaka insists was misinterpreted and not intended to imply that jailers should break the rules or use violence against inmates.

Baca’s office said Wednesday that Tanaka’s exit was voluntary and unrelated to the criticism of his performance. Yet whether the undersheriff simply chose to retire after 30-plus years or was forced out makes no difference. What is important is that Baca, who doesn’t face reelection until next year, seizes the opportunity presented by Tanaka’s departure. Among other things, he should require a zero-tolerance policy toward deputies who make false statements or engage in excessive use of force, and create a separate career track for deputies who work in the jails.

Most immediately, Tanaka’s departure will ensure that the authority of the recently appointed assistant sheriff for the custody division, Terri McDonald, isn’t undermined by a shadow sheriff. Tanaka had a reputation for protecting jailers who broke the rules and, in some cases, threatening captains who sought to discipline deputies. The last thing McDonald needs is any additional obstacles to bringing much-needed change.

While we are glad to see Tanaka go, and take it as the first real signal from Baca that he’s committed to reform, there is much that remains to be done, including fully implementing the 63 recommendations made last year by the jails commission.