The murder trial of a Utah doctor charged in his wife's death is resuming with testimony from medical experts about how they believe the 50-year-old woman died.

Prosecutors say Martin MacNeill hounded his wife to get cosmetic surgery, then knocked her out with painkillers, Valium and sleeping pills and left her to die in a bathtub.

On Thursday, Utah medical examiner Todd Grey testified he doesn't know how Michele MacNeill died in 2007 but that it could have been from a heart attack combined with drug toxicity.

On Friday's witness list are Utah cardiologist David Cragun and a forensic pathologist from Florida, Joshua Perper.

Also on deck are cellmates of MacNeill's. Prosecutors said in opening arguments that MacNeill told the inmates he was glad his wife was dead and that authorities couldn't prove he killed her.