I live within 50 miles of Sandy Hook Elementary School. On the day of the supposed massacre, we got an email from the company president of Raveis, a local realty firm we had used before. It mourned the loss of the daughter of one of their agents, Sandy Previdi.
So I looked on the Raveis website and I saw that Sandy Previdi had no listings and no history of sales. Just hired I guess, although that's not the impression the firm's president's letter had left. So I started wondering.
I also saw some drone or helicopter video taken during a weekday before the event, showing no cars in SHES parking lot, while there were plenty of cars in a nearby business or factory parking lot. So weekday, not a holiday, no cars there.
Someone reported walking through the neighborhood around SHES a few days after the event and finding every house vacant, like nobody lived in any of the houses. Things were set up to look superficially like the neighborhood was occupied, but it didn't seem to be actually occupied.
Just a few datapoints I remember from that apparent hoax event.