Jurors will hear closing arguments Friday in the trial of a Utah doctor charged with killing his wife.

Prosecutors are accusing Martin MacNeill of hounding his wife to get a face-lift, then leaving her to die in the tub heavily drugged with painkillers, Valium and sleeping pills.

A cause of death was never established. Defense lawyers will argue Michele MacNeill died of natural causes. They contend she had a heart attack and fell into the tub in 2007.

The judge says jury instructions and closing arguments will take up Friday morning before the case goes to jurors in the afternoon.

The highlight of the three-week trial was a mistress whom prosecutors argued was MacNeill's motive for getting rid of his wife.

Gypsy Willis says the affair ended years ago, and she doesn't know anything about how the doctor's wife died.