A Rio Rico man trying to protect his mother is facing charges of aggravated assault for shooting a man who was attacking her, the Santa Cruz County sheriff said.

Raul Vega, 20, was jailed on $50,000 bond in the shooting of a 35-year-old man in the chest with a small-caliber rifle Monday. The shooting occurred at a home in the 500 block of Camino Kansas in Rio Rico.

"This started out as a domestic-violence incident and escalated to a shooting," Sheriff Tony Estrada said. "The young man was reacting to the mom's boyfriend's aggressiveness toward his mom."

The boyfriend is in an intensive-care unit at a Tucson hospital in serious but stable condition after suffering a perforated lung, Estrada said.

The investigation is ongoing. Estrada did not yet know if additional charges would be filed in the incident.

Kimberly Matas