Family and friends said Michael Redlick fell in love with Danielle Redlick after her mother, Michael Redlick's second wife, died of cancer.
"In fairness to Mike, Danielle's mother was dying of cancer when they were dating," said a family friend. "She had terrible insurance."
Investigators believe Michael Redlick married Danielle Redlick's mom to help her get better health coverage.
After being widowed, Michael Redlick fell in love with Danielle Redlick, who was 20 years his junior.
Family friends soon called investigators to provide them with an outside look at the couple's relationship when they learned the 65-year-old died after being stabbed in the shoulder.
"I'd say to him on numerous occasions, 'Mike, the consequences are going to get worse here,'" Jerry Rubacky said. "'They're going to get more dramatic.'"
Neighbors said Michael Redlick would at times move out of the family home so the children wouldn't see them fighting.
The two children are expected to testify against their mother during the trial and told investigators they often witnessed tension between their parents.
The 15-year-old girl and 11-year-old boy told officials during an interview that Danielle Redlick was usually the aggressor during the fighting. Both children felt the relationship between their parents was improving in recent months up until the last several days before Michael Redlick was killed.
The boy told officials he knew something was wrong when his parents didn't show up for his baseball game the morning Michael Redlick was found dead.