MONTROSE, Colo. (KKCO) - Charges against a 33-year-old babysitter in the death of a 4-month-old Montrose boy have been dropped.

Maria Zavala-Espinosa's case was dropped without prejudice by Seventh Judicial District Attorney Dan Hotsenpiller on Thursday. According to court documents, the investigation into Angel Nieto's death is continuing, but his office was not able to prove beyond a reasonable doubt the charges Zavala-Espinosa was facing.

The dismissal motion says Nieto died from non-accidental trauma, but the evidence available can't determine exactly when that trauma happened. It could have happened at anytime within a few days of Angel's death.

Zavala-Espinoa's statements to officials were carefully reviewed before the dismissal was requested and granted. The motion reads that Zavala-Espinosa did not confess to a crime or an act of child abuse and that none of the evidence available accounts for the trauma Nieto suffered.

The motion also says Nieto's parents were told about the dismissal and did not object.