I read this eons ago. It was a sort of SF police procedural where the detectives had machines that could capture the last thoughts of a recently deceased human. The term was to deadbrain someone.
This may not be what you're looking for (the one notable count against it is that I can't recall the term "deadbraining"), but Blue Limbo by Terence M Green (Amazon link) at least explores similar themes. It's a police story setting in an unspecified near future in Canada. The title comes from a device that can bring the dead back to life - for a limited period of time, allowing them to share any information they might have on their deaths.
James Schmitz used the term dead-brain in A Tale of Two Clocks (originally published in 1962), which was also known as Legacy. I would not describe it as a police procedural. It's closer to being a spy novel. Its law enforcement was more of the counter-intelligence sort. This was part of his Hub universe (Trigger Argee is the main character), so the term may have been used in other stories which fit better.
The Commissioner looked at her. "Grab it was the dead-brain report."
This was Commissioner Holati Tate talking to Trigger Argee. Schmitz wasn't much of one for explaining technical matters, but the basic idea was that they could hook a dead person's brain up to some kind of mind reading system. The Hub also had mind reading of living brains, so this wasn't so outre. It's possible that dead-braining was done by a human being or by a psionic machine.
Eric Flint edited a release of the complete works of Schmitz in seven volumes. Four of them involved Hub stories. Trigger & Friends included A Tale of Two Clocks.
In my opinion, Schmitz is worth reading even if it turns out not to be the story you want. Trigger & Friends should be available in most library systems and is a reasonable starting point. It happens around the same time as the stories in Telzey Amberdon and before those in Telzey 'n' Trigger.