More than 130 cases assigned to the Special Victims Unit of the San Antonio Police Department have not been "properly investigated," City Manager Sheryl Sculley said at a Thursday afternoon news conference.

The unit investigates accused sex offenders and family violence cases.

Sculley said she was "appalled" and "outraged" when she learned of the problem.

"It's imperative that victims... have the utmost confidence that their case will be investigated immediately and thoroughly."

She noted that she and SAPD Chief William McManus have instituted a number of policy changes to the unit in the past decade "to improve the investigation of these particularly heinous crimes."

"My humble apologies go out to the victims whose crimes were not properly investigated. My humble apologies," Chief McManus said. "We own that, and we will fix it."

He said a number of cases were not properly followed up on or were otherwise mishandled. Some of the cases are no longer prosecutable due to statutes of limitations. New action has been taken on other cases to move ahead with possible prosecution.

"We did an audit. We noticed a change in the number of cases that were being filed with the DA," McManus said. "We found that a number of these cases... had not been properly investigated."

He noted that "a single detective" is believed to be involved in the mishandling of the cases. The detective has been reassigned, and Chief McManus could not comment on any possible disciplinary action that may occur.

Sculley said the conduct "will not be tolerated" and the city will investigate the unit to determine the scope of the problem.

"We will do a thorough investigation through the city attorney's office, independent of the police department, so that we can analyze all of the Special Victims Unit cases to ensure that we don't have any larger problem," she said.