After an almost 2 month trail...a 3 judge tribunal delivered the verdict.
The courtroom broke-out in cheers.
Though he only ruled for 17 months in 1982-83...more than 20,000 Maya died or disappeared during his short reign of terror.
Rios Montt was tried for the murders of 1,771 Maya Ixil members.
In rare testimony on Friday...he denied the charges.
An appeal is expected.