Roman Bridger showed Billy video footage of Hank Loomis having an affair with Maureen Prescott, his girlfriend's mother. Roman convinced Billy to murder Maureen because she was the reason Mrs Loomis left Hank and Billy. Roman told Billy to get an easily controllable accomplice he could pin the murder on if it went wrong (Stu) and to frame another of Maureen's lovers (Cotton Weary). Billy and Stu followed the plan perfectly.
A year after Maureen's murder, Billy and Stu killed Casey Becker and Steven Orth. Billy comes from the front of the house and attacks Casey at her window, but gets punched in the face, and knocked down. After he takes several minutes to recover, he assists Stu in gutting and hanging Casey, after she is already severely injured from stab wounds to chest, stomach, neck and legs. His choice of apparel is a generic Halloween costume that several people own, making the killer almost impossible to find. This costume is responsible for making the killer known as Ghostface throughout the Scream franchise. The next night, Billy and Stu target Sidney. After he calls Sidney and Stu chases Sidney in the Ghostface costume, attempting to kill her, Billy pops through her window as himself "comforting" a very terrified Sidney. Sidney notices a cell phone (possibly her father's as it was cloned) that drops from his pocket. She looks at him and puts a puzzle piece together, ultimately assuming he is the one that called and ignited the attack. She runs down the stairs with him shouting for her, "Whoa, Whoa, Wait... What's going on? Sidney, come back! Sidney!" She opens the door and is extremely jumpy to find Dewey holding the Ghostface mask and the cops arrived at her house. Billy is then arrested and brought to the Woodsboro Police Precinct. At the police station Burke interrogated Billy who was with his father Hank, first asking him why he has a cell phone and Billy answered that everyone has one, denying that he called and harassed Sidney. Hank defends his son saying, "Check the phone bill for Christ's sake!" then asked if he can call vital phone comp because they have the records of every phone number dialed.
Burke continued to interrogate Billy first asking him why he was over at Sidney's house. Billy answered that he wanted to see her, Burke then asked about last night pointing out that Sidney said that he came through her window last night too. Hank asked his son, "You went out last night?" unaware that Billy left the house. Billy answered that he was watching TV, then got bored and decided to go out for a ride. Burke then asked him, "Did you happen to ride by Casey Becker's house?" Billy denies it and says he didn't kill anybody. Burke told Hank that they will have to hold Billy until they get those phone records and Billy is placed in jail for the night. Dewey then shows Burke the Father Death costume saying that they sell it every five in dime in the state and there's no way to track down the purchase. Burke then asked about the phone bill and Dewey said they pulling Billy's phone bill and won't learn anything until the morning. The next morning, Dewey informs Sidney that Billy's phone records are clean and it couldn't have been him making those phone calls to her or Casey Becker which gets Billy released from jail.
In order to help clear Billy's name, Stu also calls Sidney at Tatum's house as Ghostface, promising that Sidney will find out who Ghostface is soon. This, combined with the phone records being clean, results in Billy being released from jail; however, the rest of the gang begin to distance themselves from him.
Sidney, fleeing from insensitive classmates, is surprised when she runs right into Billy. Although she sees it's him, she is not comforted and pushes him away. Not caring about how she must be feeling, he asks her if she still thinks he's the one who attacked her. She says no, but he claims she isn't the same as she used to be since her mother died. Sidney gets angry at his careless statement and scolds him. He tries to minimize what she's going through by comparing his own maternal absence to the death of Sidney's mother. He tried to justify this statement and say he wants his girlfriend back. Sidney, very emotional because of what Billy says, walks away. She runs to the girls bathroom, where Billy attacks her in the restroom (the killer wore the exact same colored pants Billy wore and he wanted to know Sidney's weaknesses), but it could be a prank or Roman's attack.
Before the party, it is unknown whether it is Billy or Stu stalking Sidney and Tatum when they are talking on the porch and later shopping at a convenient store. The girls talk of her mother's death and Tatum revealing more rumors. Rumors of other men involved with her mother (which later proved to be Billy's father). In the Convenient store, Sidney and Tatum hold a conversation about Billy and finally giving it up. Tatum says he doesn't deserve her. As she says this, Ghostface is in the reflection of store refreshment cooler. It's very apparent this is Billy, and he has targeted Tatum to get Sidney alone and possible resentment over statements she said about him.
The party occurs. He isn't invited, but is lurking around. Tatum goes into the garage for beer and she is confronted by Billy in his Ghostface costume. He kills her, and enters the house through the garage to hide out. Sidney shouts out summoning Tatum that it is time to go. After no response, she asks Stu were she is. He isn't sure. Billy pops into the door frame scaring both of them and then asking if he can talk to Sidney alone. She agrees and they go upstairs to the master bedroom and talk. Billy apologizes and then Sidney sympathetically agrees that it is her fault too for being so repressed. Billy goes on to relay he understands how she feels by some movies he has seen. She calmly tells him it is real life and not a movie. He tells her, "Sure it is, Sid. It's all... It's all... a great big movie. ..Only you can't pick a genre." They grow intimate again and Sidney saying in a flirtatious way, "Why can I be a Meg Ryan movie...? ..or even a good porno." Billy then asks her if she is ready. She replies saying she is. Soon after, Sidney and Billy have sex. The remaining guests are intrigued to find out their principal had been killed as well and flee to see his corpse. After they leave, Ghostface appears and stabs and seemingly kills Billy, and Sidney is chased once more by the killer. After Sidney is chased and she goes back into the house locking Randy out with Stu (out of his own house), Billy appears to be mortally wounded, but alive. He falls down the stairs seriously injured. She then goes to him and sees if he is alright. She helps him up saying they must get help. He insists on getting the gun and opening the door. He lets Randy in only to reveal he is the one of the masterminds behind the murders and shoots Randy in the chest area. It is then revealed that Billy and Stu took turns doing the killings while the other did the calls. They revealed Billy's motive to kill Sidney's mother, and then explained that they intended to frame Sidney's father, Neil Prescott, for everything. However, Gale Weathers intervened with the gun, only to realize that she left the safety on. Billy kicks Gale into a pillar, knocking her out, and is about to shoot her when Stu sees that Sidney is gone. Billy leaves Gale and then gets a call from Sidney, using the Ghostface voice, to taunt him. She has already called the police, and is hiding. An infuriated Billy rips up pillows with the knife while Stu talks to Sidney on the phone.
Billy then hears noises and opens up a door, to see that Sidney has tricked him by playing Halloween on a TV. Sidney, disguised as Ghostface, stabs Billy twice in the chest and smacks him. As Sidney begins to remove her Ghostface costume, Stu runs out of the kitchen and battles Sidney, After killing Stu, Randy gets up from his gunshot wound, much to Sidney's relief. However, Billy also gets up and punches out Randy. He then tries to strangle Sidney and she sticks her finger in one of his knife wounds. However, this only angers Billy and he raises his knife to stab down. Gale then gets up and shoots Billy, and he collapses. Randy predicts that Billy will come back for "one last scare", and Billy indeed did open up his eyes and let out a grunt startling the survivors. However, Sidney with a certain survivor's edge, holds the gun in confidence and delivers the killing shot to him in the forehead, officially killing Billy Loomis.
Mrs. Loomis attempted to avenge his death with another killing spree with the help of Mickey, who acted for his own reasons and who she killed, when he was useless and still useful as a scapegoat to get away with it. She killed Randy, because he bad-mouthed Billy while on the phone with her saying he was a "rat-looking, homo-repressed mama's boy". Eventually, she confronts Sidney over the death of her son. Mrs. Loomis is cleverly fought, but eventually takes Sidney captive. She was shot by Cotton Weary, who saved Sidney's life.
Sidney remembered conversations with Billy when she visited her bedroom set for Stab 3 at Sunrise Studios. She smiled at his sweet side before she thought of his sinister side. She hear noises on the set, grabs her mace, pulls her closet door against her bedroom door like before. She sees her "door" move on it own and gets nervous backing towards the window of her "room". All the remembrance, she forgot Billy did in fact came through her window through the struggle. The killer appears behind her and grabs and pulls her through "her window". Roman also mentions him after his reveal to explain his revenge plan.
Billy was referenced in the fourth installment a few times.
Trevor referenced Billy by being Jill's boyfriend at one time, crawling through Jill's window, and giving constant romantic gestures of being together. Sidney remarked that this reminded her of herself and Billy.
When Sidney comforts Jill concerning Olivia, Jill doesn't seem as bothered as she is a female "Billy". This brings on the bonding scene between Sidney and Jill, much like when Billy and Sidney made up and Sidney lost her virginity to Billy, but reciprocated. Instead, with them being female cousins, Sidney and Jill share a tender family moment, but Sidney is left with a gut feeling of familiarity as she sensed a familiar energy.
Another reciprocated reference was the chase in Kirby's house, where both Jill and Sidney run upstairs to Kirby's room. Stu originally came up and interrupted Billy and Sidney, and pretended to stab Billy leaving him "unconscious" on top of the bed and Sidney fleeing. This time, SIdney tells Jill to hide UNDER the bed and pretends she is running to get help as she flees. Like Billy, she emerges from the bed and as one of the killers.
Her very name "Jill" is reference to being a female version of Billy while being Sidney's kin. Jill has represented a hybrid of Billy and Sidney; by gestures, similar female versions of his apparel, reciprocated and similar actions, repressed anguish, wicked sense of humor and love of horror movies, and killer instinct. Charlie referenced a part of Billy by being repressed in his Love towards Kirby (the new version Sidney). Jill represented about 3/4 reference of Billy and 1/4 of Sidney while Charlie represented about 1/4 of his reference to Billy.
Arthur Himbry (probably, it could be Roman Bridger)