By Cheryl Fiandaca

SHEFFIELD (CBS) — The five people found dead in a home in western Massachusetts after a fire were the result of a murder-suicide.

The bodies of three children, a man, a woman and two dogs were found in the house in Sheffield after a fire there Wednesday morning. The fire also appeared to have been intentionally set, sources told the WBZ I-Team.

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Sources say it appears a husband stabbed his wife and intentionally set the fire killing her, their three children and himself.

The bodies of twin seven year old’s and a toddler were found on the second floor of the home along with the body of their father Luke Karpinski. His wife, Justine Wilbur, was found on the first floor and had apparently been stabbed.

Sources say it appears an accelerant, possibly gasoline, was used to spread the fire. Investigators are still searching for a motive.

“At this time, the evidence indicates that Luke Karpinski was the assailant,” District Attorney Andrea Harrington said Thursday. “The scene is secure and there is no reason to believe that the public is endangered at this time.”

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Wilbur was a patent attorney in New York and her husband also worked in the patent field.

Wilbur’s employer, Hoffman Warnick, said she was a talented attorney.

“Justine was smart, knowledgeable, dedicated and hardworking. She was a devoted mother to her wonderful children, and a true friend to everyone in our firm,” Hoffman Warnick said. “We are each devastated by loss and extraordinary sadness, but are comforted and grateful for having shared Justine’s infectious spirit and energy. We pray for her family and those who loved her.”

Multiple agencies are now involved in the investigation including forensic scientists from the State Police Crime Lab.

Cheryl Fiandaca