Victor Villarreal was sentenced to 20 years in a murder plea bargain. Paul Cantu pleaded guilty earlier and in April received 40 years.
Darvalics was 16, Villarreal was 17 and Cantu was 18 when Johnson was killed.
The Killeen Daily Herald reports the victim's relatives say he was not affiliated with a gang and was being harassed. Johnson was beaten and strangled. His body was dumped in a field. Johnson's family had reported him missing.