They were actually quadruplets, the fourth died at birth and was unknown until after the documentary.
One of the brothers was convicted of man slaughter of an 83 year old woman, who was brutally murdered after a botched robbery in 1978. He received a reduced sentence for testifying against the murderer.
Bizarrely, this incredible true story has many similarities to the overall plot and themes of the horror film Raising Cain (1992) as well as the X-Files episode Eve (1993).
Debuted at the Sundance Film Festival in early 2018.