Police allege Jacob Stockdale has shot dead his mother and 21-year-old brother and is now in a critical condition after shooting himself in the head.
All three family member appeared on US reality show Wife Swap in 2008.
On the reality show, the Stockdales were described as "devoutly religious" and had banned video games, swearing and TV.
Their father Timothy Stockdale was not home at the time, but has released a statement.
“Kathy has been my beloved wife of 32 years and a wonderful mother to our four sons,” Timothy wrote. “She loved nothing more than being a mother and grandmother.”
No criminal charges have been made.
This article originally appeared on New Idea.