Read this in UK maybe 2010, but it was a library book heavily stamped, no doubt a few years older. A reasonable-sized book of maybe 400 pages.
World building implied there were teleportation cabinets everywhere of importance, the protagonist was (I think!) some kind of artist and also an investigator with a cabinet beside his studio.
The last impression of a teleportation was saved in the system so if you got really ill or badly injured your friends/family could 'save' you by putting you into cabinet and sending you to a nearby destination. You arrived healthy and then beamed back again.
However it stated in the story that it actually murdered you at the outgoing side and kept your tissues there. At any incoming side there was always kept a reserve of tissue for people beaming in.
Protagonist was investigating some crime (I think with his girlfriend) and he went to beam somewhere and master criminal hacked the beam and created a copy of main character in his dungeon lab complex. New copy was like “you’ve got to be kidding” as evil henchmen seize him.
A few years later and hero inadvertently gets the copy back but it had been tortured and brainwashed for years. Covered in festive tattoos (that’s what it stated in the book....”festive tattoos”) and dressed in ragged and filthy jester clothes, he spent most of his time whimpering and cringing in a Gollum manner while they tried to get his backstory.
One thing they learned about master criminal (as witnessed many times by the jester) was he liked to sport with himself by “double beaming” across his lab. He entered the cabinet and two of him exited but a randomiser ensured it was a couple of minutes apart.
This ensured one bad guy was always ready to capture himself and chain him to the floor to kill him by torture. Lots of screams every time “No! No! This is wrong, it’s not meant to be you, it’s meant to be me!”
The triumphant bad guy would snigger at his hapless double and give it “Ha! Stupid!” as he commenced his lethal torture for the day.