Who Actually Killed Who In Scream?
2. Maureen Prescott
Maureen Prescott was a fleeting presence in the first Scream movie, although she's obviously a vital piece of the franchise's overall puzzle.
The very first victim of Ghostface, Maureen was killed a year prior to the events of Scream. It was only in Scream 3, though, that we got to find out the exact details behind Maureen's death.
As revealed by Maureen's abandoned son Roman, it was he who had orchestrated that death after he was rejected by Maureen upon turning up at her doorstep to start up a mother-son relationship. Angry at Maureen and at Sidney for the life that she had, Roman instigates a plan of revenge.
That plan would see Sidney's long, lost brother get in the ear of Billy Loomis to make him aware that Maureen was having an affair with his father - an affair that led to Billy's mother walking out on the family.
Not just did Roman give Billy this information, he also gave him the tip of getting someone else involved to be his fall guy. That's where Stu Macher came into the fold, with Billy convincing him to join him in killing Maureen Prescott - and that's exactly what the pair did.
Framing Cotton Weary for Maureen's murder, Billy and Stu both partook in the rape and murder of Sidney's mother.