A 23-year Atlanta Police Department veteran pleaded guilty on Monday to conspiring to violate civil rights by searching a private residence without a warrant, federal prosecutors said.

Wilbert Stallings, 44, of Conyers, a sergeant in the department's narcotics unit, faces up to 10 years in prison and up to $250,000 in fines. A sentencing date wasn't immediately set.

After a hearing before federal Judge Julie Carnes, U.S. Attorney David E. Nahmias called the actions of Stallings and his unit a "blatant" rights violation. He also said it was part of a pattern that led to the 2006 botched raid in which 92-year-old Kathryn Johnston was shot and killed in her northwest Atlanta home.

"What we've said is they developed on the team a [pattern] of breaking the rules and bending the rules that ultimately crossed over into the breaking and bending of the Constitution," Nahmias said. "That ultimately is a crime."

The charge against Stallings was an outgrowth of the Johnston investigation, Nahmias said. Stallings supervised the unit in the botched raid but wasn't charged in the case.

Prosecutors said that in October 2005, Stallings led a narcotics team executing a search warrant at an apartment on Dill Road in Atlanta.

Also on the team was Gregg Junnier, one of two narcotics officers who have pleaded guilty to charges in Johnston's death. Junnier had obtained the warrant for one apartment in the 2005 incident, prosecutors said. The team found some marijuana behind the apartment but not inside, they said. Stallings and Junnier then decided to search an adjoining apartment but no one was home and they found nothing inside.

Stallings told the team to leave the apartment and shut the door so it would appear there had been a break-in, prosecutors said.

Prosecutors argued the the incident was part of a pattern of conduct by Stallings and his team, which included misrepresenting unregistered drug informants as registered ones in order to secure warrants.

Stallings and his lawyer declined to comment on the plea.

Nahmias would not rule out the possibility of more prosecutions as the investigation Atlanta narcotic's tactics winds to a close. Federal authorities, he said, plan to produce a report of their findings that will go to Atlanta Police Chief Richard Pennington.