Though the program ended in February of this year, the battle continued to determine whether the Baltimore Police Department's aerial surveillance program was lawful. A divided federal appeals court on Thursday ruled that an aerial surveillance program used as a crime-fighting tool by the Baltimore Police Department was unconstitutional and said police must stop using any data obtained through the now-defunct program.

The 4th U.S. Circuit Court of Appeals ruled this week that the crime-fighting program was unconstitutional and police must stop using any data that was obtained during the program's tenure. When the program was active for six months, the police department uses airplanes with wide-angle surveillance cameras to surveil the city.

While the city and the police department argued that the lawsuit was now moot due to the program no longer being active, the court disagreed and said police will be prohibited from accessing data collected through the program.

The court says the program was, in essence, a warrantless search that violated the Fourth Amendment.

“The AIR (Aerial Investigation Research) program records the movements of a city. With analysis, it can reveal where individuals come and go over an extended period. Because the AIR program enables police to deduce from the whole of individuals’ movements, we hold that accessing its data is a search, and its warrantless operation violates the Fourth Amendment,” Chief Judge Roger Gregory wrote for the majority in the 8-7 ruling.