ODESSA, Texas — Prosecutors who originally charged a 17-year-old in the shooting deaths of his parents at their West Texas home have also charged his 23-year-old sister with the slayings.

Ector County District Attorney Bobby Bland says Grace McDonald of Odessa was arrested in Arizona following her indictment Monday on charges of capital murder and conspiracy to commit capital murder.

Her brother, James Gabriel “Gabe” McDonald, was arrested on a capital murder charge shortly after the March 2 fatal shootings of their parents — James Gregory McDonald and Jana Lou McDonald. The teen is charged as an adult.

Odessa police originally said the sister was home but not injured during the slayings. Investigators haven’t announced a possible motive.

Online Ector County jail records Wednesday didn’t list custody or attorney information for Grace McDonald.