John Lowe met a woman named Sue and the couple built a thriving dog breeding business in Keepers Cottage Stud, Surrey England. In 1986 Christine brought her two daughters Lucy and Stacy out to pick out a puppy. As a way to get through a hard time after Christine left their father. The girls leave with the puppy and Christine a date. 

Over time Christine moves in with John and Sue bringing along her girls to the mix. While everything starts out fine, it slowly deteriorates. 

Abuse creeps in. 

Stacy eventually leaves to start her own family. Returning for a time when Sue's health fails. After she passes, once again Stacy is out of the home. 

Christine and Lucy too have enough and attempt to leave. But the leaving has deadly consequences. Ones that clearly could have been avoided if police had done due diligence. 

Sources:

https://www.bbc.com/news/uk-england-surrey-48436674

https://www.bbc.com/news/uk-england-surrey-45251194

https://www.theguardian.com/uk-news/2014/oct/31/puppy-farmer-jailed-double-murder-shooting-john-lowe

https://dpglaw.co.uk/inquest-surrey-police-involvement-murder-of-christine-and-lucy-lee/

https://www.independent.co.uk/news/uk/crime/john-lowe-pensioner-found-guilty-of-puppy-farm-murders-9825571.html

https://www.getsurrey.co.uk/news/surrey-news/who-john-lowe-full-story-15055709

https://www.bbc.com/news/uk-england-surrey-29743897