“And he got close enough to hit him with a long .22.”
.22 LR?
Where did you read that was the weapon?
I did hear a media person say he used an AR style rifle. Yes they are possible in .22 rimfire, but would not be much of a choice at 200 years, as I have read.
From what I have read about the collateral injuries and death, I doubt it is 22 rimfire.
5.56x45 (.223 Remington) is .22 caliber.
My apologies, but I think the sound of the first shots were definitely smaller caliber. The secon shots, where the gunmen were killed were M4 at least. But the first shots sounded very low caliber.