(CNN) Authorities believe the estranged husband accused of killing Connecticut mom Jennifer Farber Dulos made an apparent suicide attempt Tuesday, according to two law enforcement sources.

Fotis Dulos, 52, was taken to a Connecticut hospital Tuesday for treatment of carbon monoxide poisoning, Farmington police Lt. Tim McKenzie said. By Tuesday evening, he had been taken Jacobi Medical Center in the Bronx, New York, for treatment in a hyperbaric chamber, Dulos' attorney Norm Pattis said.

A hyperbaric oxygen chamber could be used to treat several medical conditions, including burns and carbon monoxide poisoning. It pumps oxygen into the body.

Dulos had been in critical condition at the first hospital, UConn Health Center in Farmington, McKenzie said. Details about his condition at the hospital in the Bronx weren't immediately available.

McKenzie said officers conducted a well-being check at his house on Tuesday just before noon after Dulos did not appear in court for an emergency bond hearing. Upon arrival, officers saw Dulos sitting in his vehicle in the house's garage in obvious signs of medical distress, so they forced entry and began CPR, he said.