During cross-examination, Dr. Michael Baden, a board-certified forensic pathologist and host of HBO's Autopsy, testified that Peterson used such a maneuver before drowning Savio.
"It's extremely rare ... a healthy adult will almost never drown in a bathtub," Baden said. "My opinion is that it was a drowning. She was in an altercation, beaten up and drowned."
A second pathologist, Dr. Larry Blum, who performed the autopsy on Savio, submitted similar testimony two weeks ago.
Blum reviewed 43 cases of bathtub fatalities in Illinois and said Savio’s position wasn’t consistent with a typical fall in the tub.
“There was no blood, hair or tissue on the tub,” Blum said according to the Sun-Times. He described the murder scene as “pristine” with little blood and no splashed water around the tub making it hard to identify if the scene was staged.
A pinched carotid artery maneuver could include anything from a choke hold to the Star Trek series' famous Vulcan nerve pinch, in which an assailant applies precise pressure over barrorecptors of the carotid sinus at the base of the neck.
Peterson's defense team attacked Baden, saying that he was trying to please Fox News.
The defense suggested that the bruises on Savio's body were the result of rough sex or clumsiness.
Baden retorted: "You can get a lot of injuries from rough sex, but a hemorrhage of the diaphragm is not one of them."
Savio's death was ruled an accident in 2004. But after Peterson's fourth wife, Stacy, disappeared three years later, officials exhumed Savio's body and Baden was invited to perform the second autopsy.
Peterson, a former Bolingrbook police sergeant, is charged with first-degree murder in connection with Savio's death.