The Sole Sisters

An early morning call alerts Kate Elder her husband in on his way from the golf course to the Emergency Room. Upon arrival at the hospital, Kate is made aware the real issue is her husband Tom has been shot by a sniper. Local Law Enforcement jumps onto solving the crime, then much to quickly they place the case in their cold case files. The redirection is intended to allow law enforcement to spend their time on Fenatyl distributions and areas where the media is focused. With elections upcoming the "Political Bosses" decide there are more politically correct crimes to investigate than a local sniper shooting.
The Sole Sisters, a subgroup of Kate's True Crime Book Club managed to take on the now cold case involving her husband's sniper shooting. The Sole Sisters chose that name since they were all the only sister in their family, and therefore are used to getting their way. They pull enough strings to allow them to reopen the case and as a group of volunteers investigate the shooting, but on an extremely low profile.
They quickly discovered the original investigation was not as thorough as it could have been. Details overlooked originally begin to boil to the surface. They develop a police artists drawing of the sniper along with a partial fingerprint, the sniper's rifle, and DNA evidence. While newly discovered DNA evidence begins to tie the shooter to at least another three murders there is no record of the DNA to tie it back to an individual.
Further investigation calls attention to persons of interest in an IVF fertility clinic, sperm donors, and professional hitmen.
The Sole Sisters using Artifical Intelligence, and just plain old-fashioned on-the-ground investigation techniques end up with a suspect held for trial. But that is not where it ends.