Nature guide Gustavo Lasi, 23, (above) has confessed to raping one French student...but denied murdering the 2 female tourists...Houria Moumni and Cassandre Bouvier...claiming 2 other defendants did it.
Lasi said Daniel Vilte Laxi and Santos Vera killed the girls.
Mixed DNA evidence shows that one victim was raped by several assailants.
Santos Vera also possessed a machete that matched wounds on the victims' bodies.
But none of 8 suspects have been officially charged with the crimes that have shocked the popular tourist region.