Jaylen Fryberg, the teenager who fatally shot two fellow students, seriously injured three others, and then killed himself at a Washington state high school, invited his victims to lunch in the school cafeteria by text message, then pulled out a handgun and fired on them, investigators said. Zoe Galasso, 14, died Friday at the scene in the Marysville-Pilchuck High School cafeteria. Gia Soriano, 14, died Sunday night in a hospital. Injured were Shaylee Chuckulnaskit, 14, and the shooter’s cousins, Nate Hatch, 14, and Andrew Fryberg, 15. The five students were at a lunch table when they were shot. Detectives are digging through reams of text messages, and phone and social-media records as part of an investigation that could take months. Officials said the .40-caliber handgun the shooter used had been legally purchased by one of his relatives. It remains unclear how the boy obtained the weapon.