DURHAM - Internal investigations into the actions of three Durham police officers, including one who shot and killed a teenager, have been completed, but the public may never know whether the department thought the officers acted appropriately.

"The results of the internal investigations are covered by personnel privacy and can't be released," said Kammie Michael, police spokeswoman.

Personnel laws provide a small window into the disciplinary history of public employees. North Carolina's law shields all but the most basic information for public employees: name, age, date hired, current job and salary, most recent pay increase or decrease, and the date of the most recent change in position.

What's known is that officers Ta'Lisa Little, Brian Opitz and Anthony Harris are back patrolling Durham's streets. Michael wouldn't say when Little and Opitz were taken off administrative leave with pay, citing a November court decision agreeing with the city's position that administrative leave is not considered a change in position.

Little, who joined the department in 2005, was off-duty at a Raleigh nightclub in August when she was arrested for fighting with another woman. Her case was dismissed after both parties went to mediation.

Opitz, who also became a Durham officer in 2005, shot and killed a 16-year-old in December after the teenager pointed a gun at officers.

Harris, a nine-year veteran, was stopped by a state trooper for going 84 in a 45-mph zone in January. The trooper also reported smelling alcohol on Harris' breath but determined he was "not appreciably impaired" and asked another Durham officer to take Harris home without consequence.

James Coleman Jr., a Duke University criminal law professor, said the public at least should be able to learn whether a department believes an officer such as Opitz was correct in using deadly force.

"What would be the argument that he has a personal right to keep the basis for his using of deadly force confidential?" Coleman asked.

Coleman thinks the law should be changed to create more balance between protecting an officer's privacy rights and a police department assuring the public that it made the right decision.

Tom Nolan, a former Boston police lieutenant who has overseen internal investigations, thinks that the results of most internal investigations should remain confidential but that exceptions should be made when an officer shoots someone or is charged with a crime.

Officers make unpopular decisions that can cause someone to file a false accusation, he said. Even if such a claim is disproved, it can still tarnish an officer's career if made public, he said.

Internal investigations occur regularly in most urban police departments, said Joe Sroka, who teaches criminal justice procedure, law and ethics at N.C. Central University.

"[Internal affairs investigators are] like the watchdogs in any type of organization," Sroka said. "They know how much power and authority they have on their recommendations, but it's up to the chief to follow those recommendations."

The inquiries often resemble a criminal investigation. Investigators may subject officers to a polygraph test or scrutinize their financial history, depending on the complaint. Such inquiries protect more than just the police department.

"If police are doing their jobs correctly, you won't see frivolous litigation that cost citizens money," Sroka said.

Investigators are still reviewing the actions of officers David Rosser and Jesus Sandoval Jr. in a fatal police shooting in December and of James Cartwright, who in January shot a man who wouldn't drop his gun. Rosser and Sandoval have resumed their patrol duties. Police would not say whether Cartwright is back on regular duty.