On a summer morning in 2019, Zelimkhan Khangoshvili was walking down a wooded path in central Berlin, on his way to pray at the local mosque. It was lunchtime, and the park was filled with the sounds of children playing as their parents looked on.
As Khangoshvili walked, a man rode up behind him on a bicycle, pulled out a gun, and shot him in the back.
T…