Salt Lake City pediatrician pleads not guilty to 2011 murder of ex-wife

A Salt Lake City doctor has pleaded not guilty to the murder of his ex-wife, a university biologist.

The 49-year-old John Brickman Wall entered his plea Monday morning in a state court in Salt Lake City. Wall has maintained his innocence since Uta Von Schwedler was found dead in a bathtub in September 2011. Pelle Wall, the couple's oldest son who believes his father is guilty, sat in the front row Monday.

A judge ruled this month following a preliminary hearing that there is sufficient evidence for the case to go to trial, taking note of the pediatrician's bizarre behavior after Von Schwedler's death.

A medical examiner ruled she died from drowning as well as a fatal amount of Xanax but couldn't determine if it was a homicide or suicide.