Mackenzie Shirilla is behind bars after being convicted of double murder

A British TV presenter is fronting a new prison documentary, featuring the eerie isolation cells

The 21-year-old is the subject of a new true crime Netflix documentary

Mackenzie Shirilla and her mom Natalie were heard speaking in 'code' in newly obtained jail calls

Prosecutors have said that Anna Kepner died after being placed in a chokehold

He is known inside the prison as 'psycho'

The Crash on Netflix has brought renewed attention to Mackenzie Shirilla's case

The couple's family have spoken out since the tragic incident, saying it 'makes no sense'

The 26-year-old faces two felony charges of a making a terroristic threat

Gypsy Rose Blanchard said remorse was about to hit Mackenzie Shirilla 'like a train'

The discoveries have prompted an investigation by local police

The creepy jet has fallen into disrepair but still has a lot of its original features

The 21-year-old was sentenced to life in prison after murdering her boyfriend by driving her car 100mph into a brick wall

16-year-old Timothy Hudson has been accused of killing his stepsister Anna Kepner on a Carnival Cruise ship

Its 256 windowless cells house an average of 80 to 156 inmates each

Shyann Topping was reportedly Mackenzie Shirilla's girlfriend behind bars, but their romance 'fizzled out'

CECOT prison in El Salvador holds 40,000 of the world's most deadly criminals

The Tennessee death row inmate was scheduled to be executed last week

Matthew Perry's personal assistant has been sentenced

The pair had a series of troubling conversations

Mackenzie Shirilla and Dominic Russo dated for four years

Police are investigating the possibility of a serial killer being on the loose

Puerto Vallarta sees around two million American tourists visiting every year

Newly discovered texts show 'threats' Dominic Russo had received from Mackenzie