Detective Isabelle "Izzy" Montoya is a character in the novel Final Destination: Dead Man's Hand. She is the wife of Charlie Montoya and the partner of Warren Ackerman. Izzy used to work for Vice as an undercover officer six months before, but she transferred to Homicide, presumably because she was tired of her relentless sting operations. Izzy and Warren were both assigned to a homicide case involving a child named Danny Lavirra who was brutally beaten to death. After the two discover the body, they head over and interrogate the child's mother, Carolina Lavirra, who hinted to the two officers that her boyfriend Roberto Diaz has a habit of becoming drunk and teaching Danny to "become a better person."
After asking around and learning of more leads, Izzy picked up Warren from a diner after he had lunch with his girlfriend Shawna Engels. As they were driving in the car to an address of Diaz's whereabouts, she began to talk to Warren about letting Shawna know about some of the details of his job, advising him not to keep Shawna in the dark, despite how horrible his job was. Later that evening, Warren confessed to Izzy that he was tired of his job and was thinking about retiring once he finished the Lavirra case. He also told Izzy that he was going to open up to Shawna more, and tell her about the current case he was working on while having dinner at Merlin's Tower. He never got around to it though, and as they were leaving the tower, one of the passengers, Allie Goodwin-Gaines had a premonition about it crashing and Warren dragged her out the car with a handful of others to discuss with her the penalty of disturbing the peace. Not a moment later, the elevator crashed.
Izzy was the first person to interrogate the woman who saw the elevator crash before Special Agent Hotz and Agent McGavin took over, where Izzy watched the two in scorn as they mocked the city of Las Vegas. After Hotz was done shouting and screaming at Allie, Izzy and Sean Murphy drove the remaining survivors of the accident from the Las Vegas Metropolitan Police Department in a police van.
While driving away from the police station, a wayward traffic light snaps out of socket and swings down at the van, crashing through Murphy's side. In the process, Murphy is instantly severed in half and the force of the impact harms Izzy as well. Although she isn't killed in the crash, it is later discovered that Officer Murphy was HIV positive and since the upper-half of Murphy's body landed on Izzy, it can be assumed that she caught the virus and succumbed to its effects.
There is a possibility that Montoya didn't even catch the disease, or that a cure or treatment was eventually discovered. However, because of how strong the disease was (it was discovered in only a few days, and it could take nearly six months before doctors even know for sure) it's highly unlikely that she or Allie lived.