Officially, 12 of them have never been solved.
He was famously represented by F. Lee Bailey, who later would write a book about the case.
So this film actually has much more in common with a journalistic story than one strictly about the crime.

Carrie Coon and Keira Knightley in ‘Boston Strangler’Claire Folger
These are nobodies, he told her.
And who do you think our readers are?
A clever touch, here.

The Boston Strangler, 1968 20th Century Fox
It begins streaming Friday on Hulu.