MURRIETA - A Hemet man admitted committing a lewd act on the 5-year-old granddaughter of his live-in girlfriend and will be sentenced to three years in state prison, court papers show today.

The plea agreement was reached on the eve of trial for 33-year-old Rafael Fuentes, who was charged with one count each of engaging in oral copulation or sexual penetration with a child under 10 and committing a lewd act on a child with force, violence or duress.

Fuentes entered his guilty plea on Monday to a single count of committing a lewd act with a child under 14, a charge that was added to an amended complaint, court papers show.

Sentencing is set for Aug. 14.

Fuentes molested the girl in June 2008 at the San Jacinto home he shared with his girlfriend and three children, according to prosecutors.

The grandmother, who was about 50 at the time, had two young children of her own in the home along with her granddaughter, according to police.