Father of slain 6-year-old issues ominous threat to son’s killer who was freed early after serving just 8 years

The killer of a 6-year-old boy has been released on parole after serving only half his sentence — and the slain child’s father issuing a dire threat to the freed man. Ronald Exantus, 42, stabbed the entire Tipton family as they slept in their Versaille, Kentucky, home on Dec. 7, 2015 — but focused most…