Cayla Campos had a routine: Every night, her father said, the 21-year-old resident of Albuquerque loved to play Pokémon Go with her boyfriend as they drove through Bianchetti Park near her apartment.

“It boggles my mind,” the father, Carl Campos, said in an interview on Tuesday night. “Most 21-year-olds are out at clubs. My daughter is out playing Pokémon Go.”

But that seemingly innocuous pastime turned deadly for Ms. Campos on Friday night as she drove along Granite Avenue while she and her boyfriend searched for digital animated creatures, according to the authorities.

Just before midnight, the police said, Ms. Campos spotted two assailants trying to rob people in a nearby car.