Rudy Gillen (ルーディ・ギーレン) is criminal psychologist who went to the same school as Dr. Kenzo Tenma. He is in constant correspondence with Dr. Julius Reichwein, his former professor, who wrote to him about Johan Liebert. Because Johan had connections with one of his patients, Gillen became interested in the young man and joined forces with Dr. Reichwein to prove Tenma's innocence. The two collated evidence that Johan really existed in order to override Inspector Lunge's claim that Johan was just a figment of Dr. Tenma's imagination.
At the start of the series, Gillen has already been divorced for three years. Since he prioritized work over family affairs, his wife perceived his actions as neglectful and left him. She said Gillen paid more attention to his cassette recorder than her, and that he was "just a collector peeking into people's hearts."
Research with Peter Jürgens
Main Article: Peter Jürgens
Peter Jürgens, a recently convicted serial killer, became one of his research subjects. The man's crimes were sexual in nature, and his victims were mostly high school girls from ages 16-18. His twelfth murder of 52-year-old Hanna Kemp, however, was odd considering how out of range her age was from his usual pattern. Jürgens confessed that this last murder was performed per the request of a friend, and that his friend's name was Johan. What Gillen recorded when he was visited by Dr. Tenma was made into research material, because at that point, he, like Inspector Lunge, believed Tenma was a serial killer suffering from dissociative identity disorder; while he did believe Tenma was innocent as he claimed, Rudy thought another persona emerged from all his repressed negativity. He made Jürgens listen to the tape and asked him what he thought about it. Jürgens said he could relate to it, and that the "monster" spoken of really did exist. Dr. Gillen took it as a metaphor and agreed, saying that it dwells in him and in everyone else. Jürgens did not buy it though, telling him to "Stop your academic nonsense," and that such statements are only "textbook garbage." He insisted monsters really exist in this world, then glared at Dr. Gillen whilst tried to strangle him. When Gillen reached for the alert button, Jürgens snatched it and asked him if he was scared.
He also instructed him to visit the basement of a certain Kempf Mansion. Jürgens said he'd understand what he had been saying by going there. Upon his arrival at the Kempf Mansion, Dr. Tenma contacted him and arranged for their meeting. Dr. Gillen then informed the detective in charge of Tenma's case, Inspector Kohl, of their expected meeting at Oder Park. When he found the stairs that led to the basement, he started recording his journey down. Gillen taped some bits of information Jürgens told him, like his visit to the
same basement before killing the old woman who was sleeping on the second floor. At first Dr. Gillen only saw an ordinary storage room full of pictures of Mrs. Kemp and with a bespectacled boy, as well as the large Parisian doll Jürgens described. He was about to dismiss Jürgens' claim that this place would make him believe that monsters existed, and that his true intentions behind this murder were solely to mess with the trail of detectives following him. However, Dr. Gillen then remembered some statement Jürgens made that caused him stop for a while and load another cassette tape. In the recording, Jürgens spoke of growing up with an abusive mother, and how he used to plead help from that long haired Parisian doll from in their basement, but it would just look at him and grin. That storage room was full of pictures too, and everywhere he looked, his mother's face was there. Dr. Gillen then noticed the irregularity in the room: not only was it an exact recreation of the basement from Jürgens' childhood, but that even the photographs of Mrs. Kemp had been tampered with; the young boy in the pictures had had his head cut out and replaced with that of Jürgens' face as a child. He realized Jürgens could not have known Frau Kempf in his childhood, and that the face originally captured there was in fact, the face of the child once in the foster care of Frau Kempf.
Gillen continued listening to the tape in which Jürgens described Johan, his "friend." He said he just did what the letters from this anonymous sender told him. One day, out of the blue, he started receiving letters from a "friend" knew his past well. Tired of constantly being told this individual could empathize him, Jürgens was actually quite angered. However, as time passed, he started to enjoy receiving the weekly letters, because it sounded like they were really friends. One day, the message instructed him to visit Frau Kempf's basement. He saw the room that was set up exactly like the childhood storage room where he got punished. That basement confused him, because he had seen his own face in the photographs next to her. The sight of this triggered Jürgens' desire to kill her in place of his mother.
This confession heightened Dr. Gillen's understanding of what was going on. He searched Frau Kemp's room and found a stack of letters. The letters contained the messages Dr. Tenma showed him during his visit. This made him believe that Jürgens' "friend," otherwise known as Johan, really existed.
During Dr. Gillen's routine visits on Jürgens, he asked Jürgens about his friend. Jürgens then draws on a picture of Johan and committed suicide with the pen he was drawing with.
Dr. Tenma's visit
Upon seeing Johan's two disparate messages, Tenma decided to seek Dr. Gillen's opinion on them, and paid a visit to the psychologist's home without any advance warning. Dr. Gillen had no theory on why he was visited by Tenma, because, from what they had experienced in college together, he thought Tenma only had contemptuous feelings for him. Tenma said his visit was for him to look at Johan's messages, then he recounted what Johan did to his foster parents and Adolf Junkers, after which he stated that he needed to find this person immediately. Dr. Gillen finished Tenma's story by stating that finding Johan proves his innocence. He also asked Dr. Tenma if he had been going after his confirmation of Johan having Dissociative Identity Disorder (formerly Multiple Personality disorder).
Dr. Gillen did a mirroring technique where he tried to reconstruct what Tenma was trying to say: that Johan has a personality who murdered and another personality that stopped it. He also stated the fact that many serial killers leave such kind of messages, but most of them are using it to avoid criminal liability. Being a psychoanalyst, Dr. Gillen said that, no, serial killers are not the introverted ones, but the extroverted: sociable and persuasive. Dr. Tenma felt that he was being incriminated, so he said that Johan might just be playing with him. Dr. Gillen rolled his cassette recorder and asked Dr. Tenma to tell more about Johan. To make him more comfortable, Gillen did his usual water cooler story of his divorce with his wife.
In the University with Dr. Tenma
Dr. Gillen then started to tell Dr. Tenma a story from 20 years ago. It was about him being the best in class, and how the newly enrolled Japanese Kenzo Tenma changed that. He said Tenma was sociable and popular, with excellent grades that topped his during midterms. This made Gillen persevere more to get on the top again, until exams came. He did really well on all of his tests, but he wasn't confident with his own understanding of medical law. He used a cheat sheet pasted under his long sleeves because if he should get low grades on that subject, then all his efforts account to nothing. Tenma saw him, but did not tell anyone about it. Of course Gillen regained his former ranking as top student, but was always paranoid because Tenma knew the secret that could destroy him.
Apprehension and Escape of Dr. Tenma
Dr. Gillen had let the authorities know of their meeting. He requested of them to let him use Dr. Tenma as research subject should they succeed on arresting him. They met in front of the fountain in Oder Park. He said that after analyzing his report on Johan, he had confirmed his existence. He also mentioned his cheating in college out of blue, which confused Dr. Tenma. Then, Gillen let out an arm with a cheat sheet again, but this time, it contained instructions for Dr. Tenma's escape. Dr. Gillen confessed that he led the authorities near him, but that he now knew that Tenma was innocent after he paid a visit to Mrs. Kemp's basement. They mingled with the noisy crowd to facilitate Dr. Tenma's flight. After blending into the group, Dr. Gillen explained why he now believed his former classmate. He showed him Frau Kemp's altered picture with the boy, then added that she did not have any children. Johan was using Frau Kemp's kindness for his own sustenance and then eliminated her when she was no longer useful. Dr. Gillen believed in Dr. Tenma's innocence.
Gillen, in his analysis of Jürgens and his statements, informed Dr. Tenma that Johan can recognize murderers and control them wholly. His theory about Johan's current whereabouts was that he found his "ideal family" and joined it. He just didn't know why.
They reached the bus terminal and Dr. Gillen gave Tenma a bus ticket. He then reminded him that there are other ways to prove his innocence, but Dr. Tenma said he was not chasing Johan only to clear his name, then added that he did not hold any contempt for Dr. Gillen, because he cheated on that exam, too.
Recovering Nina's Memories
Upon Nina Fortner and Dieter's return from Prague, the two stayed with Dr. Reichwein until they received a letter from Tenma. She decided to ask Dr. Reichwein's help in recovering the childhood memories Nina had almost retrieved during her cathartic episode while in the Three Frogs. As psychoanalytic tasks like this was not Dr. Reichwein's forte, he declined Nina but offered her Dr. Gillen. Nina and the rest of the people currently in Dr. Reichwein's care visited Dr. Gillen's office. Dr. Gillen puts Nina into an hypnotic trance and starts asking questions about her mother, which produced description of Nina's mother. When Nina was probed about her father, a very short but substantial answer was given. However, Nina's sluggish demeanor due to the trance was suddenly replaced by a wave of violent narration when she recalled her brother being taken captive while the Three Frogs. Nina went into a sort of panic attack upon the memory of it and fervently narrated what happened to the Red Rose Mansion the day Johan fled. The minute Dr. Gillen asked her if Johan saw those terrible things happen, Nina displayed psychosomatic behavior which is caused by the memory of her own flesh being wounded by the thorns of the roses planted around.
Nina then passes out for a moment, and Dr. Gillen tried to rouse her by questions. Dr. Gllen inquired if she already regained her memories but Nina answered in a different voice saying "I'm not Nina, it's not my name". Dr. Gillen continues to question her but Nina does not want to say who she is. Dr. Gillen's insistence on scurrying more through Nina's repressed memories earned him a threatening behavior, in which Nina tried to strangle him for his insisting to know her name. Dr. Gillen had to put Nina out of the trance in that very moment to prevent her from doing her subconscious behavior.
After their session, an exhausted Nina was asked if she already recalls most of her memories, and she answered yes with certainty.
Gillen became interested with the unrelated murders that happened in Frankfurt in 1997. Three different murderers killed three people that did not fit their usual criteria for killing.
First he interviewed Peter Jurgens, about Johan. He said he received letters from a "friend".
Gillen and Nina travel to Ruhenheim to find out about Johan. He and Nina come across Bonaparte's unfinished drawings of Nina and Johan. Later, he witnessed Johan get shot by Herbert Knaup. He attempts to explain to police about Johan.
He is a very analytical man, as portrayed by his lack of immediate belief on Tenma's theory that Johan has multiple personalities.
Gillen also possesses a strange trait for a psychologist to have: he hates being anything but the best, and is very quick to get irritated when he feels others are viewing him in a condescending manner. This is illustrated by his desire to always have the top scores, papers, or whatever he is doing, and by how he got annoyed when one of his research subjects glared at him, saying "Don't you dare look at me like that!"
He developed a habit of recording his conversations and feels uncomfortable talking without it.
Gillen is a criminal psychologist by profession and is well-known in Europe for his numerous books in criminal psychology. He is one of Dr. Reichwein's most successful students that by 2001, he got on Germany's 50 Highest Taxpayers.
Werner Weber did not hesitate to interview Dr. Gillen in Paris during his worldwide speaking tour, him being one of few people who knew a lot about Johan and his crimes.
His book about Johan, Road to a Monster, was a best-seller throughout Europe. Weber met him at a cafe at Rue Bonaparte near the Seine river.
He mentioned his theory that Johan wasn't solely responsible for the massacre at 511 Kinderheim, as he wasn't stated to have been the one who killed the director.
When asked if he would interview Johan if given the chance, he says he wouldn't because Johan would manipulate him.
- "I became transfixed, obsessively gazing into the abyss of the human heart. I suppose it's possible the abyss gazes back into me. The depths of the human mind are filled with treacherous landscapes."
- "Tenma, that Asian man, is my friend. I'm going to save him."
- Triangulation is a method used by clinical and criminal psychologist to holistically analyse a client or subject. It consists of at least three (3) psychological methods of assessment, like behavioural observation, interview and psychological tests (projective/paper and pencil). Dr. Gillen relies mainly on his interviews and his observation, which is thereby seemed unreliable to mdern standards (taking into consideration that the series happened in the 90's).