MONTREAL - A pathologist told the Adele Sorella murder trial Tuesday that she couldn’t conclude exactly how Sorella’s two daughters died but that the evidence pointed to death by asphyxiation.

Adele Sorella is on trial on charges of killing her daughters Sabrina, 8, and Amanda, 9, on March 31, 2009.

Pathologist Caroline Tanguay noted that there were no marks on the two girls’ bodies nor were any substances detected on the bodies.

Tanguay said that the girls were likely smothered with a pillow, killed by having plastic bags placed over their heads or killed by being deprived of oxygen in an enclosed space.

Tanguay said that the last scenario was the likeliest of the three, as the family owned a hyperbaric chamber, which they used to treat one of the children’s juvenile arthritis.

The machine can relieve pain and speed healing but can also kill someone if the oxygen is turned off, as a person would fall to sleep and then die after about 90 minutes.

Earlier, a toxicologist suggested that an insulin or potassium overdose also could have caused the deaths, although no such products were found in the Laval home where the deaths occurred.

The trial continues Friday.