He served as the main antagonist of the novel Dearly Devoted Dexter where he was a serial mutilator that tortured his victims by cutting off everything on a body that was not essential for life (arms, legs, penis, teeth, tongue, etc.), leaving his victims unable to move or communicate, driving them insane.
Henker was described as being short, with large glasses. His accent also implied that he was Cuban.
Henker was a vengeful character, which was his whole reason for torturing people, who turned out to be members of his old unit, who he believed betrayed him and gave him to the Cubans in El Salvador.
For most of the book, Henker is only mentioned and not seen. He is only seen toward the end of the book, when he captures Dexter outside of his house. During the course of the story, he tortures several people, though only kills one, an agent from Washington named Daniel Chester Burdett. The rest, he would simply torture them until they were a "stub".
During his early life, Henker offered his his services to the United States military as a torturer. His comrades, who included Sergeant Albert Doakes, nicknamed him "Danco" after a vegetable slicing machine. The joke was that Dr. Danco, like his namesake, made sliced "vegetables". Dexter makes a similar conclusion about his victims, before the name is revealed, calling them "yodeling potatoes". During a covert operation in El Salvador, he was turned in to the enemy in exchange for several prisoners. Henker was eventually released and goes to Miami, looking for revenge on his former comrades.
At the end of the story, while he is torturing Doakes, filling out the word "TREACHERY", Deborah and Chutsky rush in. Chutsky, being without half of one of his arms and legs, is easily knocked out, but Deborah kills him with two shots to the chest upon entering.
Henker's method of torture was rather brutal. He would cut out their tongues, and then play a game of "Hangman" with them. Every time they would guess wrong, he would cut off a part of their body. Since their tongues were cut out, their guesses wouldn't be understandable, and therefore, they would always guess wrong ("I don't think that's right," said the Doctor. "Although, perhaps if you had a tongue, it might have been.")
Henker cuts off all of their limbs, eyelids, lips, ears, and their noses, he also forces them watch their own dismemberment by hanging a mirror above them while they are on his "operating table." The victims are sedated through the use of different kinds of chemicals in order to prevent them from dying, as well as causing some brain damage in the process.
Note: Only one man was actually killed by Henker during the course of the story, Dan Burdett. Most of the rest were tortured until they were a stub.
- Manuel Borges (Manny Borges)
- Dan Burdett
- Frank Aubrey
- Kyle Chutsky - Only had half of his right arm cut off, and half of his left leg.
- Albert Doakes - Only had his tongue cut out, hands and feet cut off.
- Oscar Acosta - he was the victim that Danco missed, having escaped the clutches of the Doctor in a high speed flight by car.
- Wendell Ingraham - He was to be sliced up after Doakes, but the Doctor was killed before getting to him, though he was being tortured by being made to observe Doakes' dismemberment.
- Andy Lyle - who lives in Davie, and was scheduled to be after Ingraham, still living in blissful ignorance.
Of the other members of the squad that Danco was targeting, two were already dead, and one was still in the field.
- Dexter Morgan - Henker attempted to kill him twice, first indirectly when Dexter and Deborah crashed from the bridge in a car chase trying to pursue him (and nearly drowned themselves as a result) and secondly he considered Dexter a witness that he doesn't needed, sedated him and was thinking to kill and/or multilate him after he finished Doakes, but he was interrupted on this one.
- Deborah Morgan - was injured and nearly died (technically heart even stopped for a few minutes) when car chase after Henker went wrong way.
- It is widely believed that Dr. Danco was the basis for the Showtime series character George Washington King, known as "The Skinner" during Season Three. Both used torturing methods to get what they wanted; however, the Skinner was ultimately a lot less brutal than his counterpart.
- "Henker" (Dr. Danco's real last name) is German for "executioner."
- Henker liked to listen to Tito Puente while "working" on his victims.
- The plates on Henker's white van read CHOOSE LIFE.