So this Bosnian guy tried unsuccessfully to kill his mother-in-law using an anti-tank missile. He probably doesn't play Call of Duty a lot because as an expert in the field, I could have told him that it is very difficult to kill infantry-in-law using an anti-tank missile. You have to aim really hard and cannot rely on the splash effect of the explosion like you would in case of a common grenade.
The best way to carry out the kill would have depended on the circumstances. If his target were to be running from room to room, a submachine gun like the mini-Uzi or the MP5 would have been perfect for the purpose. If he were to be at a longish distance, say encamped in her neighbor's garden or high atop a tree, an M16A4 rifle would have been great because it gives you both the range as well as the accuracy. If he had lots of time on his hands and wished the endeavor to be totally bereft of any danger, he could have used a Barrett .50 cal sniper rifle from, half a mile away. This rifle does make a loud noise, but that should be drowned out by the sound of your neighbor trying to kill his mother-in-law with an anti-tank missile.
As an aside, I like how the reporter sympathetically explains how "She cannot be killed be (sic) conventional weapons".