[El Gato]

"A man with a gun who was spotted in the woods near the school on the day of the incident was an off-duty tactical squad police officer from another town, according to the source."

Who was the person that one of the students witnessed "handcuffed on the ground"?

[Uncle Chip]

That would be nice to know. I doubt that it was Manfredonia or the off-duty officer. But as Vance said, when the dispatch went out thee police swept the surrounding area and detained everybody and anybody they could find to make sure no one got away.