The In Crowd (2000)

During one heated argument too many, cruel bitchy Sandra was accidently pushed to her death down a flight of stairs by her abused tormented sister, Brittany Foster. Brittany (who uses her sexuality to get what she wants) convinced Kelly to burry her sibling within the posh East Coast country club grounds. When she finds out Kelly's going to confess their sins, she convinces Kelly to go out on an oceanic boat trip where she puts the moves on her (Kelly) Convinced it's real Kelly removes her life jacket whereupon Britt shoves her overboard, before sailing away back to shore. Thanks to her plaster leg cast weighing her down Kelly eventually drowns. Her beau Bobby smells a rat when he finds Britt's lip gloss in the boat.Dr. Henry Thompson who's she's been secretly seducing decides to break it off and come clean about everything, in response she takes a golf club too his skull framing Adrien Williams.Back in the looney bin Adrien drugs Dr. Amanda Giles and with Bobby's help escapes. She fools Brittany into believing her sister is back from the dead, thereby digging up her sister's shallow grave. Enraged at this trickery she tries to use a pair of hedge clippers on Adrien followed by drowning her in a pool, but Bobby raises the alarm and now everyone knows Britt's a muderous psycho.As the story closes we see her once again using femme fatale tricks to ensnare a gullable orderly to open her cell.