I loved this show when it was on TV and I’ve enjoyed the books, too, even  if most of the ones I’ve read have been kind of corny. That’s okay – they’re relaxing. With the books,  Jessica Fletcher is always the 1st-named author, but Jessica is a fictional character from the TV show Murder She Wrote which ran from 1984 to 1996. In the show Jessica is an amateur sleuth and  author of mysteries. She’s portrayed by Angela Lansbury.  

Murder, She Wrote: Murder in Season
By Jessica Fletcher and Jon Land 
2020 / 
Read by Laural Merlington 8h 29m  
Rating: A+  / cozy and historical mystery –
(#52 in Murder She Wrote series)

Only 5 years after it premiered as a television show,  Donald Bain, an established US fiction writer, began writing cozy crime novels to go along with the show. Fletcher’s name is used as the primary author and Bain considered himself the “ghost writer.”  He did this almost until his death, from 1989 until 2015 – that’s 25 years and 44 books. He died in 2017!  Since then the second writers have included Jon Land for 5 books and Terrie Farley Moran for 6 books (so far).  Murder in Season is book #52 out of 58 through 2024. 
https://en.wikipedia.org/wiki/List_of_Murder,_She_Wrote_novels

The narrator for the audio books  has also changed a 4 or 5 times over the years but the readers keep reading or listening. https://www.fantasticfiction.com/f/jessica-fletcher/murder-she-wrote/

Rumors about concerning possible real locations for Cabot’s Cove. This articles is by Donald Bain’s daughter: https://roadtrippers.com/magazine/jessica-fletchers-cabot-cove-maine/

When Jessica’s backyard is dug up for a new septic system, a large, old wooden box turns up. Inside the box there are human remains and a documents folder with documents in it. What, and how, in the world?  Meanwhile, Cabot Cove has been found to have an extraordinarily high number of homicides compared to the rest of the US so a reporter is coming to write about that.  

Murder in Season gets into historical fiction because what a reporter has come to Cabot Cove to investigate is not the high murder rate he tells the citizens of the town,  but his real interest is what happened to a certain group of early investors and the money and treasure they brought, what they found, what they invested in, and how their descendants have fared since then.

That’s the basic frame story. Along with the box and human remains, the box also included the journal of John Henry Cabot, one of the original founders of Cabot’s Cove and in whose honor the town was named.  There are murders in both the frame story and the interior story.

https://en.wikipedia.org/wiki/Jessica_Fletcher
https://en.wikipedia.org/wiki/Murder,_She_Wrote
https://en.wikipedia.org/wiki/Angela_Lansbury

https://www.greenhealthymaine.com/blog/atlantic-black-box
This is a very interesting piece about a mixed race group on an island off the coast of Maine.
Also see This Other Eden ~ by Paul Harding my blog entry for the book which was selected for the Booker Short List. This is historical fiction about a group of mixed race people residing for decades on an island off the coast of Maine. There is plenty of evidence for the slave trade stretching up the Maine coast.