LOS ANGELES — It had all the makings of another turbulent moment for the Los Angeles Police Department, an agency once notorious for an “L.A. Confidential” style of heavy-handed policing, hostile relations with minorities and corruption. Two months after triumphantly announcing the arrest of a suspect in a brutal beating at Dodger Stadium, the police admitted that they had arrested the wrong man, and charged two other people with the crime.

But unlike other potentially explosive episodes that have rocked this department over the decades, there were no indignant denials or attacks on critics. Instead, the police chief, Charlie Beck, wrote an op-ed article in The Los Angeles Times explaining what had gone wrong and expressing regret at some of his own public comments. “We can do much better,” Chief Beck wrote.

The moment reflected what has been a revolution for the police department that was once the model for Sgt. Joe Friday and “Dragnet.” Twenty years after the police beating of Rodney King was caught on videotape, and 10 years after the Justice Department imposed a consent decree to battle pervasive corruption in the Rampart Division, this has become a department transformed, offering itself up — in a way that not so many years ago would have been unthinkable — as a model police agency for the United States.