A mother’s desperate 911 call reporting one of her sons waving a gun on the family’s front porch ended with two of her sons and her husband shot by at least one police officer Tuesday night in Pittsburg.

Officers were dispatched to the home on the 1500 block of Kingsly Drive at 9 p.m. after the mother called police saying her 20-year-old son, Rigoberto Gutierrez, was acting irrationally and had pointed a handgun at his father through the house’s security screen door several times, said Capt. Ron Raman, a spokesman for the Pittsburg Police Department.

Gutierrez, who the mother suspected was on drugs, was on the porch demanding entrance to the house when police arrived, Raman said. At that point, he had put the gun in his waistband, Raman said.

Officers ordered Gutierrez to drop the gun, but he refused to comply, Raman said. When he reached for the weapon, at least one officer, a 20-year law enforcement veteran, opened fire, hitting Gutierrez in the leg, Raman said.

Other rounds fired by police went through the security screen door near Gutierrez and struck the father and the suspect’s 17-year-old brother, who were standing inside the house behind the door, Raman said.

The father was shot in the stomach and the younger brother in the leg.

All three family members were hospitalized, Raman said. The father was treated and has since been released. The teenage brother is in stable condition and expected to recover from his injuries.

Gutierrez is also expected to recover from his injury. Raman said he will be transported to county jail when released from the hospital and charged with assault with a deadly weapon and additional weapons-related charges.

Gutierrez has prior arrests for drug possession, resisting an officer and petty theft, police said.

His gun was recovered by officers at the house.

As part of the Contra Costa Officer Involved Shooting Protocol, the incident is being investigated by the Pittsburg Police Department and the Contra Costa County district attorney’s office, Raman said.

The investigation is ongoing and, Raman said, more information will be released as it becomes available.

Kevin Schultz is a San Francisco Chronicle staff writer. Email: kschultz@sfchronicle.com Twitter: KevinEdSchultz