Since it took him quite a while to expire it was probably birdshot. Double ought buckshot at that range would probably have alleviated the perp's primal sexual urges right on the spot where he stood.
Some self proclaimed "experts" say that birdshot won't stop a determined attacker, but way back when I was just a teenager my uncle killed a 400 lb black bear with two 12 gauge # 8 shells while quail hunting in south FL. He and the bear surprised each other when he walked around a dense stand of baygalls where the bear was feeding on palmetto buds, and the bear reared up on his hind legs about 10-15 feet away.
Uncle Cecil said that he was so shocked by the bear's sudden move that without even thinking he threw his Browning automatic shotgun up to his shoulder and fired two loads of # 8s into the upright bear's chest. The bear then dropped down to all four legs and ran a short distance before he collapsed.
The FL fish and game commission sent a pair of it's law enforcement agents down to inspect the bear's carcass which was hung up in the local ice house, and at that time, early 1950's, they said it was the largest bear ever killed and weighed in south FL.
I have no doubt that at close range #8 will ruin your day and knock the perp off his feet to be sure.
Number 2 steel shot on the other hand will drop a man at 200 yards, closer and we don’t even want to talk about it.
I’m thinking of getting a rifled slug barrel and a scope for some distance practice.