"At least the real ones are, not so much the neutered M80s they sell commercially these days."
That may depend on the State.
Also, since it was left behind in the house, maybe it was the "good old stuff" from before it became illegal in that state.
Still, it sure seems odd to mix up dynamite sticks with candles.
"Other homes in the area were also searched as a precaution."
By permission? Seems like that sucked if not. By you, this is probable cause?
"Although it is illegal to possess dynamite, fireworks or firecrackers in Connecticut, charges are not expected to be file [sic] since the family had no prior knowledge that they were in the possession of explosive devices."
That's funny, because when I lived in New York, we used to make "Fireworks Runs" to Connecticut to buy the "Good Stuff" in fireworks. (1950s, early 60s) Connecticut was a "Free State" back then.