I don't know much about hitmen or the case in question, but off the top of my head it doesn't sound like a terrible choice.
You can buy a .22 rifle without any sort of record-keeping, they don't cost that much, neither the gun nor the ammo will raise any eyebrows, they're still very lethal at close range, and depending on the ammo you use they don't make that much noise, making it easy to fire off a couple shots and leave undetected.
You can buy a .22 rifle without any sort of record-keeping, they don't cost that much, neither the gun nor the ammo will raise any eyebrows, they're still very lethal at close range, and depending on the ammo you use they don't make that much noise, making it easy to fire off a couple shots and leave undetected.