Since 1990, police dogs trained to apprehend suspects in Prince George's County (Md.) have instead attacked and mauled police officers, canine handlers and other law enforcement agents at least 43 times, according to public records and other documents.

In one case, an FBI agent was forced to shoot a police dog that attacked him during a standoff with a gunman. One corporal suffered bite wounds to the arm and stomach -- and then was bitten on the face two months later. A German shepherd named King attacked its police handler three times and sent as many as 40 other people to the hospital during its career.

Experts said it is rare for well-trained police dogs to attack the wrong people. Several police departments with canine squads similar in size to the Prince George's unit reported few -- if any -- cases of dogs biting officers.

Savannah, Ga., Police Chief Dan Flynn, former supervisor of the canine unit with the Miami-Dade Police Department, could recall only a handful of attacks by the dogs on police. "That would be enormously high," Flynn said of the number of bites in Prince George's. "We never got up to those kind of numbers."

Although the attacks on law officers by police dogs have not been previously disclosed, the unusual frequency with which Prince George's dogs have mauled civilians has been well established.

The U.S. Department of Justice began investigating the county canine squad more than two years ago after numerous complaints and lawsuits by people who had been bitten by county police dogs.

The investigation was begun in 1999, as The Washington Post published internal police records revealing that dogs handled by eight canine squad members had bitten 60 civilians in an 11-month period in 1998.

Court records and interviews indicated that police canine officers sometimes allowed their dogs to attack whomever they encountered and at times ordered them to bite suspects who had been handcuffed or otherwise subdued.

Since then, police officials have announced a variety of changes to the unit, but despite the promised changes, there are indications that the county's canine corps remains troubled.

A few of the attacks in Prince George's occurred in training classes for the dogs and handlers, but records show most of the accidental bites happened while police were on patrol. In almost all cases, officers sought emergency medical treatment.

"If a department has continual problems with personnel being bitten, there is something operational or trainingwise that needs to be addressed," said Russ Hess, executive director of the U.S. Police Canine Association. "In most cases, it's probably not the dog's fault."