Mexican authorities have said from the beginning that Bruce Beresford-Redman's account of his wife's activities before she disappeared in the days before her body was found don't match witness testimony.
"Everything that we have seen certainly points to Bruce as ... the only suspect," said Former Los Angeles County prosecutor Robin Sax, who has no connection to the case. "I think there's no one else for them to look at."=
Shortly after his wife's body was recovered, Beresford-Redman requested she be cremated, according to Mexican authorities who say their investigation is nearly complete.
It was a revelation the family found "disturbing," according to a lawyer.
Beresford-Redman's sister told "Good Morning America" this week that the idea that her brother-in-law might have been capable of such a horrific crime saddens her.
"I think everybody can be capable of murder. And I'm really sad if he did," Carla Burgos said. "She was a very, very pleasant person."
An arrest in the case has been delayed, pending forensic testing, but Monica Beresford-Redman's family said it wants justice immediately.
"We want the person that murdered my sister," Jeane Burgos said. "I want this person in jail to pay for the rest of his life for what he did."
Burgos said she doesn't believe Beresford-Redman's story that his wife disappeared after she left by herself to go shopping.
Police officials said there is no record of her having left the hotel grounds.
Security guards check all cars that come and go.
"It's just like horrible, it's just like so hurtful," Jeane Burgos said. "I can't even express how much pain is inside my body."
The couple's two children are back in Los Angeles. A judge has granted temporary custody to their father's parents, but their maternal grandparents are fighting for custody.