Police were called to the 200 block of North Vine Avenue in Ontario for an unknown trouble-related call for help, according to a police news release.
Officers learned that a man allegedly broke into the home at gunpoint and victimized the 44-year-old woman who lived in the residence before fleeing the area.
Ontario resident Daniel Anthony Aguirre, 20, was arrested in the 500 block of West Holt Boulevard when police searched the area for a man fitting his description according to the release.
The weapon was recovered and determined to be a realistic looking pellet gun.
He was taken into custody without further incident and later booked into the West Valley Detention Center in Rancho Cucamonga in connection to the sexual assault.
Detectives are also investigating a similar incident that occurred about an hour earlier in the 100 Block of North Pleasant Avenue.
In this incident a similarly described man was unsuccessful at making entry into a residence and fled before officers arrived.
Detectives believe the man they arrested may be responsible for both incidents according to the release.
The investigation is ongoing.
The police are asking anyone with information to call Ontario detectives at 909-395-2001.