More grim news today from the Baltimore Police Department: a 29-year-old city cop on the force for four years was arrested today and charged with stealing money and drugs from an undercover detective posing as a drug dealer and conducting an integrity sting. The charged officer, at left, has been identified as Michael Sylvester.

The city force has had a problematic history and mixed results with internal stings, which officials have routinely said are conducted routinely but rarely catch cops in wrongdoing. The last one I can find that we wrote about was a year ago when an undercover cop tried to get another cop accused of being brutal to hit him.

The cop did, got arrest and got found not guilty by a judge who said the accused cop might have had good reason to hit the undercover officer.

In 2006, a female officer was convicted of illegal gambling after a sting caught her at a secret poker game. Another officer was indicted in 2003 on charges that she made a false arrest by claiming to have found drugs on a suspect that in fact had been planted by Internal Affairs.

The widely publicized sting came in 2002, hailed then as the first of its kind targeting Baltimore police, when Officer Brian L. Sewell was charged with planting drugs on a suspect. Allegations swirled over missing evidence, a poorly done investigation, stolen surveillance photographs and a story put out by police that turned out not to be true.

The case had appeared clearcut. Sewell had responded to a call for a man selling drugs in a park. He confronted a man fitting the description, searched him, said he found drugs and arrested him. But the drugs he said he had found had actually been placed on a park bench by Internal Affairs. But detectives made several mistakes, including calling in a false 911 call that included a generic description of a suspect. That enabled the officer to say the man he had stopped fit a description from a caller.

But Sewell didn't arrest him right away. Instead, Sewell picked up the planted "drugs" (in reality ivory soap) and took them to another call where police had detained a man coming out of a vacant house. Police said Sewell arrested the man and added a drug charge to him -- the drugs he had taken off the bench in the park. Unfortunately for police, detectives didn't see Sewell pick up the drugs from the bench because they had actually been targeting another officer they thought was dirty. And they didn't see Sewell's arrest of the man at the vacant house.

But they couldn't account for the missing "drugs", sparking a days long scramble to figure out what had happened. Meanwhile, the man Sewell had arrested lingered in jail. It wasn't until a detective decided to look into other cops who had reported making drug arrests around the time of the sting stumbled upon Sewell, pulled the drugs he had inventoried with the department and discovered they were soap.

The arrested man was quickly released after having spent 10 days in jail and Sewell was arrested. Prosecutors were later forced to drop the criminal charges because evidence went missing as part of an unrelated break-in to the Internal Affairs office by a disgruntled officer upset he had been transferred because of a fight he had with his wife. Sewell was convicted of internal administrative charges and fired, but that conviction was overturned by an appeals court and he retired from the force. He died in August 2003.