Police Capt. Richard Conklin said witness statements and other reports were handed over Tuesday to the Stamford state's attorney's office. He said the investigation is largely done, but continues.
Conklin said there's no recommendation whether there should be criminal charges.
The fire destroyed the $1.7 million Victorian home of New York City advertising executive Madonna Badger and killed her 7-year-old twins Grace and Sarah Badger, 9-year-old daughter Lily Badger and Badger's parents, Lomer and Pauline Johnson.
Badger escaped along with her friend Michael Borcina, a contractor who had been renovating the house.
Authorities say the fire was started by embers in a bag of discarded fireplace ashes.
Get Eyewitness News Delivered