Not much is known about Hobbes' past, other than that he had a brother named Art, who gave him a nephew, and that he was once married to a woman named Marcie, who left him. Hobbes grew up to be a fine lawman and police detective, who captured the gruesome serial killer Edgar Reese, who taunted him and called him at all hours of the nights all the time he was chasing him.
Detective John Hobbes made his debut in the film at the prison where his famous captive, Edgar Reese, was being held to await execution, questioning his boss, Detective Stanton, as to whether or not the governor had disapproved of Reese's execution. Going inside to Reese's cell when requested, Hobbes, showing a mutual respect for his enemy, shook hands with the condemned convict, before he began to speak a language Hobbes believed to gibberish. Bidding Reese farewell after hearing a riddle from him, he later watched his execution, Reese sing "Time is on my Side" as he was gassed. Meeting his partner and fellow detectives at a bar later, Hobbes enjoyed some humorous campany about their jobs and beer. Later that night, he is woken up by a phone call in the middle of the night, blocking the number after no one answers. The next morning, Hobbes hugged his nephew, Sam, before he went off to school, and sat down with his brother, Art, declaring he never regretted having them there and that if his wife, Marcie, had really loved him, she would never have left him. After arriving at work later, Hobbes informed his partner, Jonesey, of the phone call he got that night after bringing up Reese, before receiving another phone call that tells him where to find a "clue". Arriving at that apartment, Hobbes and Jonesey find a dead man, killed in a similar fashion to Reese's style. After Jonesey showed him the same riddle Reese had told to him written on the wall behind a door, Hobbes became very shocked. Discussing the possibility that Reese had an accomplice back at the station, Luke, another detective, told Hobbes of a plaque in the basement with one of the riddle's names written on it, with him realizing that they were both written there, with the name between them removed. Researching who the name might be, Hobbes manages to discover it was Robert Milano, a decorated cop from the 60s who committed suicide. Going to Stanton with his findings, he is informed by him that Milano was not a good cop, but a corrupt one(Milano was framed for murders he didn't commit, but was innocent).
Being told by Stanton to just keep whatever he found to himself, Hobbes was given a tape of Reese to view, which he does with Jonesey after cinversing with him about the possible copycat killer to Reese and trying to trace Milano's relatives. Watching the tape with Jonesey, they discussed what languages Reese was speaking, Hobbes identifying one as Dutch but that the first was just gibberish, which Jonesey questioned. He later goes to see Gretta Milano, daughter of the dead cop, who agreed to discuss her father with him on the grounds that he not repeat it or who told it to him. Hobbes learned that Milano had been framed for murders he didn't commit and killed himself to evade prosecution. She, however, would talk with him further and admitted she'd rather he not call her if he had more questions, but asked him if he believed in God, to which he answered yes. Later that night, his house received another phone call with no answer, just like before. The next day, a language expert identified the first language Reese spoke in the tape as Simian Aramaic, a bible language, which puzzled Hobbes and Jonese. Going with this, he also pointed out that in high school baseball, Reese had been right-handed, but here is shown to be left handed. After this, Hobbes received another phone call about a "clue", with he and Jonesey finding another murder victim, who he recognized from the previous night where they walked by each other, and he looked him in the eye, also finding another clue. Hobbes later visits the cabin where Robert Milano shot himself discovering a strange book on demons and the name "Azazel" written on the basement wall and painted over. Discovering the meaning of the name, he went to Gretta Milano again and asked her about all this, but she simply advised him not to take this case, with him replying he had to as it was his job. Later, Hobbes and Jonesey read over the translation of the Aramaic, which didn't make as much sense as they hoped, but Hobbes continued to work with the tape.
Not long thereafter, Luke came to him and began to act very strangely, singing the same song as Reese, which others begin to do the same, but none of them remembering it when he asked them. Following an old man who drew his attention outside and suspicious of what he learned at the cabin, Hobbes let Azazel know he knew who he was after calling out in Syriac Aramaic, which seemed to surprise the demon somewhat. Afterwards, as it continued to switched from body to body by touch and threatened him, Hobbes became shaken and freaked out. Again going to Milano, Hobbes, though he didn't believe everything she said right away, learned that Azazel was a mortal demon and that he might just be one of the few able to kill him as someone he couldn't enter by touch. Later, he appeared at a church by her request, learning that Azazel had come after her. Comforting Milano, he conversed with her about Azazel and said they shouldn't be seen together like this anymore because of him. At the station later, Stanton told Hobbes that he was a suspect in the two murders Azazel had done, as his lucky coin and fingerprints were found at the second victim's house. Ordered to go home, Hobebs found that Art had a black eye and that Sam had done it. Recognizing this and his strange manner when he passed him outside, he believed that Azazel has possessed him and grabbed him, only to find he had switched into his friend, Toby, who ran with Hobbes' address book. Chasing him until he ran into a teacher(on purpose), he sent Toby home, and was forced by Azazel to kill his host, who drew a gun. Shocked when the demon simply transfered to a young woman and began to sing the song again, Hobbes asked Azazel why not just kill him, being answered that the demon was still having fun.
Later that night, Hobbes tried to convince Stanton that the teacher's death was a setup, which he found ridiculous, before he told Art and Sam nearby to go home and lock up. Afterwards, he went back to the station, but was simply allowed to go home by Stanton. Before that, Hobbes and Jonesey conversed about God and the reason for all things happening, also getting phone call from Milano. Once home, he called her back and tehy discussed what Azazel and the other demons like him wanted, to which she answered "the fall of civilization", also establishing that Azazel could only survive for one breath outside a host, which would last for 500 cubits. The next morning, after he greeted Sam, Hobbes tearfully discovered Azazel had possessed Art and made him commit suicide after writing something on Sam's chest. Telephoned by Jonesey, he then discovered that the demon had given a false testimony to frame him for the murder of the teacher, as Azazel had done Robert Milano. Hobbes and Sam quickly packed before Luke could arrive and take him to the station and they fled the house and, after evading the police, went to Milano's, where Hobbes and her rationalized that the reason Azazel could take over anyone in spirit form, even those he couldn't by touch, was because he would be fighting for his life, and therefore, be that much more powerful. Telling Milano to take Sam somewhere they would be safe, Hobbes returned to the cabin, knowing Azazel would follow him. Along the way, he talked with Jonesey, whose phone was tapped by Luke and Stanton. Later, Stanton and Jonesey arrived to arrest him, but Jonesey wanted to make it seem like he committed suicide and let him go. Stanton quickly put an end to this notion and they force Hobbes to put down his gun. However, to Hobbes' shock, Jonesey suddenly shot Staton through the head, revealing Azazel had possessed him. Chased into the cabin, Hobbes tackled Azazel when he tried to kill Jonesey and they fought for control of the gun, resulting in Jonesey being shot in the chest.
Revealing his knowledge of Azazel's limitations, Hobbes sat down and, asking the demon if he knew why Milano had come out here when he died, lit and began to smoke a poisoned cigarette, taunting Azazel that now time was on his side as they would both die together. After the demon swore at Hobbes, he, apologizing to Jonesey, shot him in the forehead. As he began to feel the effect of the poison, Hobbes was taken over by Azazel, who tried desperately to get his car keys and get to a new host, but Hobbes' body died of the poison before he could. However, the demon then entered the body of a cat nearby and fled into the night, making Hobbes' death in vain.
Detective Hobbes was a very skilled and decorated lawman, who caught at least 8 top class criminals in his career. He was also highly intelligent and cunning, able to fool Azazel, a demon much older than himself, into a trap.
Detective John Hobbes was a very serious man about his work, but also very good with humor. He was kind and loving of his family, and showed great comfort towards Gretta Milano for her past sufferings and her helping him against Azazel.