Police told that Terry Janway, Dalton's grandma, shot & killed him & his grandfather Jack before killing herself when police arrived at the family home.
After calling 911, Terry, 68, is the main suspect, according to Muskogee police.
Johnson's fifth-grade nephew's school is mourning his death after the NASCAR driver's in-laws' tragedy.
Ronia Davison, Sadler Arts Academy principal, told the Daily Press that his students loved him.
He could sense people' needs and help in any way. Davison called Dalton “absolutely precious and just a good friend to everyone.”
“He had a loving smile and he just carried himself in a way that just made him approachable and friendly and someone you wanted to be around,” the principal added.