Gray is a cop in the Gotham City Police Department in 3027.
History
In Artifacts,on August 8,3027, he and Moira finally found the Batcave in efforts to stop Mr. Freeze. The two found many objects there, including the trophy room, the run-down Batcomputer, and the Batsuit, but nothing helpful in stopping Freeze.
He finally found out that Batman pasted a binary code on the titanium supports of the Batcave. They used the code to access the Batcomputer.
With the information they gathered, a team led by Gray took down Mr. Freeze. The police later used the cave as their new base of operations, with a large Batman monument standing in between.