Doctor: Peterson's third wife not susceptible to falls

A neurologist who treated Drew Peterson's third wife says a condition she suffered from called "cervical vertigo" wouldn't have caused her to fall.

The testimony Friday at the former police officer's murder trial is important because the defense has suggested the condition could have caused the fall that killed Kathleen Savio in 2004.

Peterson has pleaded not guilty to first-degree murder in Savio's drowning death.

Her body was found in a bathtub, and her death was initially ruled an accident. It was reclassified as a homicide after Peterson's fourth wife, Stacy Peterson, disappeared in 2007.

Dr. Gene Neri told jurors Friday that cervical vertigo makes people feel unsteady but that those with the condition are less likely to fall than those without it because they're more careful.