It was a routine drug arrest in one of Baltimore’s more troubled neighborhoods.

But it has become a flash point sparked by video from one of the officer’s body cameras.

The public defender’s office looked at the video and contended it showed an officer planting evidence in a trash-strewn alley.

Baltimore police countered with a more complicated explanation. They are investigating whether the officer had legitimately found drugs but, realizing he had forgotten to turn on his body camera, reconstructed his find. His body camera captured both him hiding the drugs and then finding them. Authorities said that would be improper but would not be an effort to make a false arrest of an innocent citizen.

The video led prosecutors to drop the felony drug case against a suspect who had been jailed for nearly six months. Baltimore police said one officer has been suspended and two others were placed on desk duty amid an internal investigation.

(BaltimorePolice/Twitter)

The case is among the latest to show the challenges faced by the growing number of police agencies whose officers wear cameras, including questions of when officers should start and stop recording, and how much discretion they should be given.

The Jan. 24 video shows the officers in the back of a vacant rowhouse. One places a zip-top bag full of drugs under a board in a back alley, walks out and then returns seconds later to retrieve the same bag.

“Planted the drugs,” the public defender’s office said in a statement that made the video public.

Baltimore Police Commissioner Kevin Davis told reporters that his department is “looking to see if the officers in fact replaced drugs they had already discovered in order to document the discovery with their body-worn cameras.”

Davis played three clips from body cameras from several officers that precede the one released by the public defender. These videos showed officers searching the lot for some time and finding some drugs, though not necessarily the same heroin seen in the later video. “Right here,” one officer says. “There’s more here,” adds another.

There is a five-minute gap between the end of that video and the one that shows the officer hiding the bag. “Why were the cameras turned off and then turned back on?” Davis said. “I don’t know right now.”

The video that went viral on the Internet is yet another troubling episode for a department under a federal consent decree because of a documented pattern of discriminatory and abusive practices.

Christy Lopez, a Georgetown University law professor who led the Justice Department group that conducted reviews of troubled police departments, including Baltimore’s, said she was “not surprised” by the video.

She said her office’s review “documented a culture in which that kind of behavior can occur.” Lopez said she sees little distinction in whether drugs were planted or merely repositioned for the camera. “It’s still a lie, either way.”

The incident occurred on Eagle Street in southwest Baltimore. The 1 minute 19 second video shared by the public defender shows three officers in an alley, with one appearing to hide the bag of drugs. The officers then walk out of the alley, and the officer who had the bag activates his camera, apparently forgetting it records the 30 seconds prior to him hitting the switch, thus capturing his placement of the bag.

“I’ll check here, hold on,” the officer says as he returns to the alley, lifts a rock and finds the bag.

Davis said that even if the officer’s intent was to re-create what he had missed recording earlier, the video “shows an officer apparently placing evidence and recovering evidence in a way that is inconsistent with the way police officers do business.”

Debbie Katz Levi, the head of the public defender’s special litigation section, said that if the officer did re-create his investigation for the camera, he should have said that in his charging document used to justify the arrest.

“We already have issues that place the credibility of officers into question,” Levi said. “Until Baltimore officers have earned the trust of the city, they should not be able to have the discretion to turn these cameras on and off.”