"No lawyer, no adult, no access to family members, (he) makes a statement," said Eric Griego, the uncle of 15-year-old Nehemiah Griego.
The teen was alone in an interrogation room at sheriff's headquarters in downtown Albuquerque when he gave a detailed confession of how he killed his parents and three younger siblings, the Albuquerque Journal reported Wednesday.
The Griego family sat down with the Journal to discuss their concerns about the case.
"With what we've all learned about brain development, something must have gone wrong with his brain," Eric Griego said.
The family said Nehemiah was in no condition to give a statement to authorities, especially not alone.
"For us the hardest thing is that it became fact," Eric Griego said.
The family objected to the way Sheriff Dan Houston and investigators for the Bernalillo County Sheriff's office have revealed details of Nehemiah's confession, presenting them as fact and as evidence that the teen was planning to go on a killing spree after slaying his parents.
"As far as we know, that whole narrative that he was going on this grandiose shootout was based on a scared 15-year-old in the middle of the night, in the sheriff's department," Eric Griego said. "If any of us would have been there, we would have just told him to shut up."
The family doesn't dispute that Nehemiah killed his parents and three siblings but they don't want him to be tried as an adult.
New Mexico law automatically transfers 15-, 16- and 17-year-olds into the adult system if they are charged with first-degree murder.