this case kind of reminds me of the Karen Slover case except that these in-laws did the wet work themselves -
Murder of Karyn Hearn Slover
Police then began to suspect that Michael Slover Sr and his wife Jeannette (Karyn's ex-mother- and father-in-law) had performed the murder over custody issues, as Karyn had expressed interest in moving away to pursue her modelling career and take her son Kolten with her. Before arresting the Slovers the investigators had a veterinary geneticist perform a DNA analysis on the animal hairs found on the duct tape, which was matched to hairs retrieved from an animal brush that had been used on the dogs Slover kept on his business property.[2] The police used this evidence to arrest the Slovers, which would be later thrown out during an appeals process by the Slovers.[1] The Slovers, which included their son Michael Slover Jr, were all arrested with the charge of first degree murder, although Michael Sr and Michael Jr were both given the additional charge of attempting to conceal a crime. Michael, Jr. had been at work, which was confirmed, but he repeatedly called his parents that day, which made him a suspect in concealing the crime.
On May 18, 2002, the Slovers were all found guilty of first degree murder and were later sentenced to 60 years in prison, with both Michael Jr and his father receiving an extra five years for the charge of concealing a crime.[3]
https://en.wikipedia.org/wiki/Murder_of_Karyn_Hearn_Slover
you can watch the full episode here -
Forensic Files - Season 11, Ep 8: Concrete Alibi
[video=youtube;6LwYh9MPPdA]https://www.youtube.com/watch?v=6LwYh9MPPdA[/video]