Mystic River
Nobody likes to see someone go down for a crime they never committed, but that's exactly what happened when Dave Boyle (Tim Robbins) took the blame for the murder of Katie Markum (Emmy Rossum). Dave, who confessed to murdering a pedophile, was threatened and coerced by Jimmy Markum (Sean Penn) into admitting that he killed Katie. Jimmy violently murdered Dave as retribution and dumped his body in the Mystic River—only a few hours before Katie's actual killers were identified.
Friday the 13th
While Jason Voorhees didn't survive Camp Crystal Lake, his mother did—at least, for a bit. Driven mad by the death of her son, Mrs. Voorhees (Betsy Palmer) went on a murderous rampage in order to enact revenge upon the counselors who were too busy canoodling to notice that Jason was drowning. The final survivor of the massacre, Alice (Adrienne King), decapitates Mrs. Voorhees.