I watched this movie a long time ago. I initially didn't remember it much because my English was not so good but after seeing the character I propose approved to another site, I re-watched it and now, I'm sure he is at least worth a discussion here.
Conspiracy Theory is a 1997 action movie made by Richard Donner. It stars Mel Gibson and he interprets taxi driver Jerry Fletcher, who is haunted by fleeting and frightening visions. Roaming the streets of New York, he entertains his clients with obscure plots known only to him. Everyone takes him for a paranoid. Only Alice, a young prosecutor at the Ministry of Justice, who has lived as a recluse since the assassination of her father, agrees to listen to him.
The character/his acts
Dr. Jonas (Conspiracy Theory) is a doctor specialized in the psychiatric field working for the CIA. He kidnaps Jerry and brings him into a mysterious place. Seeing him, he says he was looking for him for a long time. He asks if he had been talked to someone. Jerry answers he does not know what Jonas is talking about. Jonas pricks it with a syringe. The substance proves to be a hallucinogen because Jerry begins to hallucinate. Jonas continues to ask Jerry with who he talked? Because Jerry refuses to answer, Jonas brings down the seat on which Jerry is lying in a basin of water. As he pulls it up, he keeps asking the same question. Jerry suddenly bites his nose and manages to escape the building.
He runs to see his only “friend” Alice in his office but he is arrested and transferred into a hospital. Handcuffed, he asks Alice who came to see him to switch the charts with the patient to whom he shares the room. She agrees and the next day, the patient is found dead, apparently from a heart attack. Alice is convoked downstairs and she meets Dr. Jonas there and also Lowry, another agent working for the FBI. She tells where Jerry is and they all go to find him. Jonas notices that Alice saw the bandage on his nose and tells her that a dog bitted him. However, Jerry simulates a heart attack and escapes the hospital’s staff while they transfer him. The officials spots him and a chase ensues. Jerry disguises himself into a nurse to escape. Jonas approaches Alice. He asks her why Jerry talks only normally to her. She answers that he maybe has a crush on her and that he saved her from a mug some time ago.
Later, Jonas breaks into Jerry’s apartment. Searching Jerry, he finds a painting with Alice riding a horse on it. He orders to get everything known about her.
Alice begins to investigate some people Jerry talked about. These people received conspiracy newsletters Jerry makes. She discovers that all of this people except one died under mysterious circumstances. She goes to the office of the last person, Henry Finch, only to find Jonas. He reveals that he was responsible for the MK-ultra project. Jerry served as a guinea pig in CIA experiments aimed at manipulating the minds of individuals into murderers by exposing them to hallucinogenic substances, terminal experiments on sensory deprivation and electroshocks to induce a vegetative state. But in 1973, the program was stopped. Jonas claims that research still continues. He also tells Jerry has killed her father because a photo supposed to be in his wallet when he was killed was found into Jerry’s safe deposit box. So according to Jonas, Jerry stalked Alice because he was an obsessed pervert.
So Alice is under Jonas’s “protection”. At some moment, a pizza is delivered to her name although she has not ordered one. Jonas stops the pizza to being carried away, opens it and finds a letter written by Jerry. The psychiatrist asks Alice to interrogate him with a micro to know what Jerry did and to who he talked. She accepts the offer. She goes to the place Jerry told her to go, embarks in the car and goes for a ride. Dr. Jonas follows them with his men. Unbeknownst to both, a third team follows them. Knowing he is tracked, Jerry stops the car in the middle of a bridge, goes to the other highway, takes another car and goes to Connecticut. Confused, Alice makes calls with her mobile, allowing Jonas to trace them. The duo goes to Alice’s father location. Then Jerry regains little by little his memory back. Jerry had been "programmed" to kill Alice's father, who was a judge, but he couldn't bring himself to do so because he had fallen in love with her; another man was therefore tasked with killing Alice's father instead of him. Jerry arrived too late to save the father, but swore to the dying father to protect Alice.
Jerry and Alice are found by Jonas and his minions. Jerry is captured and taken in a helicopter. The plotters try to shoot Alice down but she escapes them by fleeing into the forest. Held prisoner in a disaffected wing of a psychiatric hospital, Jerry is injected with a substance by Jonas who tells him that it will make him believe that he killed Alice. Jerry mocks Jonas saying he can’t hurt him anymore. Jonas retorts that he will be the judge of that.
It also turns out that the third team that followed Jerry, Jonas and Alice earlier was a secret agency who wants to use Jerry as a bait to arrest Jonas. The leader’s name is Lowry and Alice goes to him. He tells everything about this organization and asks Alice to help her to find Jerry but Alice knocks him off, preferring to find him alone. Succeeding to find him, she gives him a kiss and when they were going for another, Jonas makes irruption. Agent Lowry and his men also arrive and a shootout ensues between them and Jonas’s minions. On his side, after taunting Alice, he knocks her before she can go against him. Jonas fights with Jerry and he ends falling into a basin, held in the water by Jerry with a broom. Jonas manages to grab a gun on his ankle and shoots several bullets at Jerry, before being shot by Alice and killed.
He says to Alice he works to make penance about what he did when he worked for MK-Ultra but this is just lies since it is revealed he continued the project illegally after the program was closed.
Except for the torture at the beginning of the movie, he does not do so much onscreen but the effects of his crimes are clearly shown in the movie. His horrible torture and brainwashing on Jerry left him paranoid, hence explaining his behavior during the movie. About Alice's father, she works to elucidate his death during the movie so the effects of his assassination is still in the movie.
He has men at his disposition and he does not abuse them but there is no proof he genuinely cares for them either.
He is the main antagonist in the movie. The other are his minions and they are not shown to do anything outside his command.