Technically speaking, if one fired a .223 (5.56) it could kill at that range. If you are speaking of a .22LR or .22L, it is almost entirely impossible. The only way that a .22 could kill at that distance, is if you fired it at a very high angle and the bullet somehow landed in the eye socket, or punctured an artery in the arm. Just my $0.02
Possible- yes. Likely? No. Most "assault" rifles have a much shorter effective range. Hitting someone at a mile with a relatively low powered rifle would be a matter of chance.
"Before you criticize someone, you should walk a mile in their shoes. That way when you criticize them, you are a mile away from them and you have their shoes."~ Jack Handey
Theoretically possible out to a mile. 200 yds would be stretching it though
Possible, but not likely. The drop of a .22 bullet at one mile is so great you would need to aim several hundred feet in the air above him.
To kill a mocking bird
It all depends on how big the piece is.
You can fire a 44 mag out of a rifle in excess of a mile.
Atticus in To Kill A Mockingbird
Yes it is and it is also the most accurate sniper rifle in the world, with a bullet spread of .3 centimeters up to a mile+ away. it shoots a .408 round which can penetrate armored helicopters and lightly armored vehicles.
Something chambered in .50 caliber would be better. But shooting at a mile's distance, success is much more reliant on the shooter's skills, luck and comfort with their tools as the equipment itself.
In excess of a mile.
Over a mile.