Because in all five in Maryland yesterday, and in the one in DC last night (which has yet to be connected to the MD five) the victim was killed by a single shot from a .223 caliber rifle. And none were head-shots.
If you do a drive-by with a handgun, how many people will you kill outright with a single shot from a handgun? With head-shots disallowed and misses disallowed.
That statement is misaligned with Wash. Post article... the woman shot at Leisure Place(?) was shot in the head as she sat on a metal bench.