Police officers arrived at the home after the woman's teenage daughter called authorities to say she had been sexuality assaulted. She was able to flee to a neighbor's house for safety.
Police described Vanwinkle as a friend of the mother, who was staying at the home.
He served multiple prison terms in Indiana on child molestation charges and pleaded guilty to misdemeanor domestic violence in Colorado in 2012.
“The possible penalty is life without parole or if the district attorney chooses, to seek the death penalty it is punishable by death, but the DA will not have to make that decision until later in the case,” Judge David Thorson told Vanwinkle on Monday.
Authorities have scheduled an autopsy of the victims on Tuesday to determine an exact cause of death.