Story number one is about Jeff McDonald. He married Collete Stevenson on September 14, 1963, and had two kids. Jeff was intelligent. He studied thorastic surgery. He became a Green Beret physician.  

One night Jeff called 911 to report that there had been a stabbing. His wife had been stabbed 21 times in the chest and 16 times in the neck. His children had also been brutally murdered. Jeff sustained a few injuries but reported that after finishing washing the dishes, his daughter had wet the bed, so he went and slept on the couch. He said men broke into the house with a woman who was holding a candle and chanting "Acid is groovy, kill the pigs."

Police thought the story was a bit fishy, but they didn't have more to go on. 

He was formerly charged in 1970 of the deaths at an army hearing. He was dishonorably discharged and move to California for a successful career. His civilian trial began in 1979. 

He was convicted of the murders, it was found out that he found his daughter in bed after wetting the bed and killed her. After that, he killed his other daughter and wife to cover it up.

Story number two is another family of four. In a small town which people call "Little Washington". The husband and wife were attacked in their bedroom by intruders, while the daughters slept through the attacks.  Police couldn't find any evidence of the involvement of the kids so turned their attention to the husband. 

He was very much into Dungeons and Dragons. Our own social media coordinator is very into role-playing games and explained it to the Sleuths. The husband had made friends at his college around the game D&D. They decided to murder his family in exchange for a part of the inheritance. 

The connection between these two stories will surprise you.