Aspen Hill Road and Conn Ave.
You can also see the Gate of Heaven Cemetary to the right
The gas station is to the left (off-white roof) the gas pumps are under the canopy (next structure) lined up perpendicular to Connecticut Ave which is the multi-lane road running north/south.
The major parking lot directly across the street is approximately 10 feet above the gas station grade elevation and the grade increases as it reaches the shopping center stores (dark roofs on slight angle).
The parking lot in the upper-right corner is the back half of the shopping center where the first Michael's store is located.
The large white square at the top of the photo is another grocery store.
Trust me, the shooter could not see the gas station from the cemetary. I gaurantee you that, because of how the pumps are located and the direction they face, the shooter was sitting in a vehicle directly across the street in the big parking lot.