A sister of a sword-wielding Florida man, who police say strangled his wife before being fatally shot by a sheriff's deputy after an Illinois car chase, believes the couple carried out a suicide pact.

Belinda VanDommelen says Bobby Curtis Jr. and Lisa Curtis long had been tormented by the 2005 death of their 17-year-old son who was killed by a car as he walked in Panama City, Fla., where the family lived.

The couple's ending July 26 came two days after they bolted from a mental-health evaluation.

VanDommelen says the couple always just wanted to be with their late son.

She says the Curtises lost their Florida construction contracting business after last year's BP oil spill devastated that region's economy.