For more on the Martin MacNeill case, watch " HLN After Dark" tonight at 10 p.m. ET on HLN.
Michele MacNeill was found dead in the bathtub in her family's Pleasant Grove, Utah, home on April 11, 2007. Her husband, Dr. Martin MacNeill, is now charged with first-degree murder in her death.
WATCH MORE: Hear Dr. MacNeill's 911 call for help
MacNeill's behavior before and after Michele's death created a lot of suspicion among his own daughters, particularly regarding his relationship with his mistress, Gypsy Willis. MacNeill allegedly hired Willis as the family nanny just one week after his wife's death. During a preliminary hearing in 2012, Rachel MacNeill said her father hired Gypsy even though he knew Rachel had quit her job and offered to care for the younger children.
So could Gypsy be tied to Michele MacNeill's death? Could she have been the motive for the death of her lover's wife? Our experts break down all the evidence tonight at 10 p.m. ET on HLN After Dark!