At least one of the victims was dodgy

 

"The victims were renting their house on a 21-year cheap lease from the person they sold it to at a knockdown price. The Du family had challenged that sale in court as a ruse to dodge debts."

Read more: http://www.dailymail.co.uk/news/article-1382713/Family-dead-knife-wounds-Northamptonshire.html#ixzz1LP8iQFqe