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COLTS NECK, N.J. (CBS/AP) — The Monmouth County prosecutor says the deaths of four family members in a Colts Neck mansion fire is now being investigated as a quadruple homicide. Monmouth County Prosecutor Christopher Gramiccioni says they have positively identified the bodies of Keith and Jennifer Caneiro, and tentatively identified the bodies of their two children, 11-year-old Jesse and 8-year-old Sophia.

Gramiccioni says the deaths happened prior to the home being set on fire.

This comes as authorities arrested the owner’s brother on an arson charge stemming from a blaze in his own nearby home. Officials say Paul Caneiro was charged with aggravated arson on Wednesday.

The fire at Paul Caneiro’s home, about 10 miles away from the mansion, was the same day as the one in Colts Neck. Authorities had speculated that the two fires could be related but haven’t charged anyone in connection with the mansion fire.

Gramiccioni said during a Wednesday press conference that he can’t confirm or deny that Paul Caneiro is a suspect in the deaths of his brother and family.

Colts Neck is about 50 miles south of New York City, and the upscale enclave is home to a number of celebrities, including Bruce Springsteen. Former “Daily Show” host Jon Stewart and his wife operate an animal sanctuary there; Queen Latifah sold her mansion there in 2015.

Property records indicate the Colts Neck home was owned by Keith Caneiro. He and Paul Caneiro are listed as executives at a technology firm, Square One.

It wasn’t immediately known if Paul Caneiro had retained an attorney.

Three severely burned bodies were found inside the mansion, and Keith Caneiro’s body was discovered outside, Gramiccioni said Tuesday. Officials did say that Caneiro was shot.

Firefighters responded to the fire around 1:30 p.m., and it was still burning hours later. Video showed firefighters battling the blaze as smoke poured from the roof of the two-story home, which is surrounded by fields and includes a large swimming pool.

Helicopter footage showed a sheet in the middle of the yard next to the house, with police tape cordoning off the area.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)