The Blood Slide Boxes are objects in DEXTER and the Dexter Book Series. They serve as "Trophy Cases", housing the many blood slides that Dexter Morgan has collected over the years for his many victims. There are two Blood Slide Boxes: one box from prior to the end of Season Two and the destroyed box that existed from Season Three to Season Seven.
BackgroundDexter didn't always collect blood slides as trophies of his victims. Rather, he spent many of his early years simply killing just to kill before meeting a man named Alex Timmons. It was in his meeting with Timmons (and subsequent slaying) that resulted in him deciding to keep trophies of his kills, to admire them and remember them fondly as he was proud to have ended their lives. Timmons became Dexter's first blood slide and the first of many that would fill his boxes.
Both boxes are stored neatly in a hidden compartment within Dexter's air conditioning unit inside of his apartment. Removing the face of the unit and revealing a top compartment hides the box from prying eyes. The unit is fully functional, so there's no reason for any visitors to mess with the device.
Both boxes have storage for 50 slides however Dexter never manages to fill either of them. It's made of a fine oak finish, polished with a white plastic holder for each slide, numbered down the side from 1 to 50. It's unknown if Dexter keeps any identifying information elsewhere in the box or on the slides to tell one victim from another.
Blood Slide Box #1
The first box. First seen when Mike Donovan's slide was placed neatly next to Dexter's previous victims, this box often was shown after every kill he made. In the first season it's existence is also known to Brian Moser, Dexter's older biological brother. As part of a game he takes one of the slides (belonging to what is presumed to be Valerie Castillo) and draws two eyes and a smile to create a "smiley face" out of the blood droplet on the slide.
This box is nearly dumped by Dexter in fear that he could be identified by a mere child following the murders of Jorge Castillo and his wife Valerie (with her body resurfacing, as part of Brian's game). Dexter views several of his slides, belonging to Alex Timmons, Cindy Landon and Gene Marshall debating whether or not to dispose of it overboard the Slice of Life. Dexter decides to keep the box, adding more slides to it by the end of Season One (however he does not add his brother Brian, saying that he's "not a trophy".)
The box becomes crucial in Season Two as it is discovered by Sergeant James Doakes as he investigates Dexter's apartment in search of evidence linking him to the Ice Truck Killer. What he ends up finding is more than what he bargained for, however he's unclear of what it all means and thus takes the box with him an airport, leaving them in his car as he flies to Haiti. He asks an old friend if he can analyze some slides for him, however the box is found in his car by the FBI (after Special Agent Frank Lundy names him a suspect as the Bay Harbor Butcher). The box goes into police custody at this point, no longer belonging to Dexter.
As Dexter arrives home realizing that the blood slide box he had kept hidden for so long was not in the air conditioning unit. Already feeling that the FBI was closing in on him, his fears heighten when they come knocking on the door and ask him to come along. He slowly heads out with the FBI, feeling that he's finally been exposed as a serial killer and is brought into the Miami Metro Police Department'. As he approaches Frank Lundy and the-then Captain' Tom Matthews, he looks down to notice the slide box sitting on the table before him. After being asked to sit, Matthews blatantly (and somewhat coldly) asks to explain this. In one word Dexter says "Trophies" and Lundy confirms his suspicion...before finally revealing that they found the box in James Doakes's car and that he was their prime suspect. Dexter sits there with a shocked look of disbelief, real because he honestly felt he was exposed and is then ordered to analyze his own blood slides.
Dexter takes the box with him to scrape blood from each slide, filling up multiple tubes while he carefully replaces each slide in the box. He carefully wipes the box to remove his own fingerprints. After he finishes, the box is closed and returned to evidence...where it's finally shipped off to FBI archives outside of Miami Metro Homicide's jurisdiction. Lieutenant Maria LaGuerta feels there's more to the investigation than what was concluded (following Doakes's death), she still wishes to clear her friend's name. She even learns that a man named Leonis was authorized to analyze some blood slides for Doakes, thus explaining her knowledge of the box.
Many years pass before the box is ever revealed again, following the death of Travis Marshall Laguerta (now Captain) discovers a blood slide at the crime scene. Shocked by this discovery, she begins to remember the Bay Harbor Butcher Investigation and how she felt back then when she believed Doakes wasn't responsible. After some detective work of her own, she gains authorization (probably due to her higher ranking than her days as Lieutenant) to obtain (off the books) the original blood slide box. Filled with all the slides from before, this box is now currently within Maria LaGuerta's possession.
Blood Slide Box #2
Season Three-Season Six
The second box. First revealed while Dexter Morgan is at a dentist appointment some time after the events in Season Two, some flashbacks reveal that he killed Cal Rooney and placed his slide (along with a couple others) in new box claiming in monologue that he's met "new people". For the most part this box returns to the same location as the previous one, slowly filling up through the course of the series. Not every victim receives a blood slide though most do.
In the middle of Season Four Dexter moves out of his apartment and gets a shack out back from his house with wife Rita Morgan. The blood slide box makes the transition, staying in a hidden compartment inside its structure. It's in this location that Dexter breaks one of his slides (for a victim he killed that didn't fit the code). At the start of Season Five, Dexter torches the inside of a shipping container he was using (apparently) filled with data on potential victims and criminals. As he's leaving, he takes the blood slide box with him not yet ready to let it go.
Partway through Season Six, Dexter manages to kill Walter Kenney and attempts to add his blood slide to his box. Already feeling like Walter's final words had meaning (that he'll eventually become old and decayed like him, a shell of what he once was), Dexter sloppily tries to insert Walter's slide into the box as it teeters on the edge of his bookshelf before it ends up crashing to floor causing several slides to slip out and at least one breaks. Dexter feels he lost order in doing this, though he may have found a way to rearrange them. It's uncertain which slide broke, likely being Kenney's.
The box is shown just as it always has been, the slides neatly placed backed inside (though they are most likely out of order, and it is unknown if Dexter kept the broken one). However, following the increasing pressure from his sister Debra Morgan and the fact that Maria LaGuerta had been reported finding a blood slide lost by Dexter at Travis Marshall's crime scene, Dexter determined that he couldn't hold onto the box any longer.
After claiming the life of one more victim, Ray Speltzer (whom had proved difficult for him and was a centerpiece in the struggle between Dexter and his sister)...he takes one last look at the box, running his fingers across the slides as he looks on with a depressed, empty feeling. Struggling to pull himself into the next action, he places the box on Speltzer's chest and presses a nearby button in the Morgue. Dexter had set Speltzer up on the bed that wheels itself into the cremation chamber, thus hitting the button forced Speltzer (and the box) to slide into the flames. Dexter bids farewell to his "friends" as the box burns to ash along with Speltzer's body.
- Dexter often admires his bloodslides, opening the box and running his fingers gently across the top as the glass slightly clatters. This can be seen as him appreciating his collection of killers, proud of those he's killed in the past.
- There have to date only been two blood slide boxes and now neither are in Dexter's possession (one is in LaGuerta's and the other has been destroyed in flames). Since LaGuerta died, it's possibly still owned by the Miami Metro Police Department.