Last month, prosecutors filed felony charges against one officer accused of beating a female bartender, and six other officers were removed from street duty after they were accused of assaulting four businessmen in a bar.
Superintendent Philip J. Cline, who took over as superintendent in November 2003 and had been expected to retire later this year, said at a news conference he would stay on until a replacement was found. He did not take questions from reporters.
"Mayor Daley has given me a once-in-a-lifetime opportunity to lead the best police department in the country, and I thank him for that," said Cline, 57.
To the city's police officers, he said: "I encourage all of them to rise above any controversy and stay focused on the mission."
Mayor Richard M. Daley would not say whether he asked Cline to leave now; he said Cline had wanted to retire a year ago but stayed at Daley's request.
"The vast majority of Chicago police officers are dedicated, hard working professional men and women who perform their jobs diligently every day," Daley said. "Unfortunately, the actions of just a few officers," can tarnish the department's image.
The department was internationally vilified after the bar surveillance footage of an off-duty officer pummeling a female bartender half his size was broadcast worldwide through 24-hour news channels and on YouTube.
Police said the footage showed Anthony Abbate, a 12-year veteran of the force, punching, kicking and throwing 24-year-old bartender Karolina Obrycka to the floor after she reportedly refused to continue serving him drinks. Obrycka suffered bruises to her head, neck, back and lower body, according to her attorney, Terry Ekl.
Officials have been criticized for waiting a month to arrest Abbate and for initially charging him with a misdemeanor.
In his brief statement on Monday, Cline also alluded to the apparent effort by police officers to help Abbate enter and leave a court building without having to face the media outside. That caused an outcry in the media about the way police officers protect fellow officers accused of breaking the law.
Videotape of the other confrontation, on Dec. 15, has not been seen by the public. Police had been called to the bar that night, but a sergeant who was among the officers involved in the fight waved them off, Cline said. He announced last week that the six officers had been taken off street duty.
Cline didn't say Monday what role the beatings played in his announcement, only referring to them obliquely as "these times of challenge."
He has clearly been embarrassed, saying Abbate "tarnished our image worse than anybody else in the history of the department," and that he was "disgusted to witness this type of conduct" by officers.
After the beatings came to light, Cline said he would change the way the department responds to allegations of misconduct, including moving faster to get officers accused of misconduct off the street.
He stressed improvements Monday in the department of 13,500 officers and 3,000 civilians made under his leadership.
"Three and a half years ago, Chicago was the homicide capital of the country," he said. "Mayor Daley gave me a mandate as the new police superintendent to reduce homicides and shootings and to make Chicago the safest big city in America. Since that time the men and women of the police department have answered that call."
Cline was born in Chicago and began his police career in 1968. His first beat was the tough Cabrini-Green housing projects. He was named chief of detectives in 2001 and first deputy superintendent two years later.