"We want the person that murdered my sister," Jeane Burgos tells ABC News. "I want this person in jail to pay for the rest of his life for what he did."
In an interview with CBS News, Burgos added: "I am bleeding inside, because I can't even imagine that I'm not going to have her with me ... I'm not going to sleep, and I'm not going to sit down until I bring justice to her life! … It was a brutal murder that was committed against my sister."
Another sister, Carla Burgos, tells CBS the family is desperate for answers. "That's what we want: justice," she says. "It wasn't fair for her."
Beresford-Redman was found dead in the sewer of a Cancun resort on April 8. Her husband, former Survivor producer Bruce Beresford-Redman, with whom she was reportedly having marital problems, was told not to leave the country.
A source tells PEOPLE that the family still had not decided where Monica would be laid to rest – in Rio de Janeiro, where she was from, or in L.A., where she had lived since 1990.
Reporting by ELAINE ARADILLAS