The deputy discovered Zach critically wounded in the back seat. He later died.
When police returned to Holder's home to investigate, they found four more victims -- her son Dylan and his girlfriend, and the Suttles' siblings. Dylan was dead and "Hana" died Monday at the hospital, according to Powers.
"We are still investigating," said Powers. 'We are working toward angles based on the two notes, but we want to try to go in without preconceived notions and try to verify her thoughts...We don't want a grassy knoll three years from now. We are dotting all our i's and crossing all our t's."
Mark Couch said his family was so upset, "we can't describe it."
"We know these people inside out," he said of the Holder family. "Dylan and his brother would spend the night at our house and they would spend the night at theirs. We did stuff all the time as a family. I refuse to believe it. This is incomprehensible."
The night before the shootings, Zach and his friend Nick Couch had watched an Ultimate Fighting Championship.
"All we know is that it was [Zach's] mom and we can't see her doing that," said Nick. "We knew her pretty good and we were at the house all the time. I just don't know why it happened. We are just trying to figure that out now."
"He was probably the closest friend I had," he said.