The wounded woman whose name has not been released pending notification of kin out of state said she didn't have phone service and asked Hoodman to call 911.
The daughter died and the mother was taken to a hospital in critical condition, said West Jordan police Sgt. Drew Sanders.
Sanders said that the mother, "with a bullet wound to her head ... got in the car, drove down the street and honked the horn" to alert Hoodman.
Sanders said that after speaking to Hoodman, the woman drove her blue Hyundai a half-block to her own home on the 8300 block of Bard Lane (1320 West), parked in the driveway and went inside.
The woman was still there when officers arrived.
Later Wednesday, officers executed a search warrant at the home, where they said they believed they would find a handgun.
While the reason behind the shooting was not immediately known, Sanders said, "It appears that it was on purpose.
Audrey Orrillo, who had been a friend of the mother's for some time, said that as soon as she saw news footage of the neighborhood, she recognized the woman's home.
Orrillo said she couldn't believe the news.
She said she lost touch with the woman about a year ago, after Orrillo moved to West Valley City.
"She was so nice, she would do anything for anybody," Orrillo said, adding that they used to have barbecues at the mother's house and that the mom liked to camp.
But behind the scenes, the mother and the daughter were struggling.
The mother lived on Social Security benefits, had fibromyalgia and was behind on paying the property taxes on her home, Orrillo said. According to the Salt Lake County Treasurer's office, the mother owed $8,819.62 in unpaid taxes and has been delinquent since 2008.
Orrillo said the mother had moved with her daughter from California and used inheritance money to pay cash for her West Jordan home, but had gotten behind on the taxes.
Orrillo said the daughter had few, if any friends, and took online classes instead of traditional school. She said both the mother and daughter stayed at home and rarely went out.
"They were all [that] each other had," Orrillo said.
The combination of stresses on the mother may have caused her to snap, Orrillo said.
"I guess that does get to people, they don't know where to turn," she said.