Title: I Know What You Did Last Summer (TV series)
Content:  what happened last summer. ; Ashley Moore as Riley, Lennon's friend and drug dealer and Dylan's best friend. She is part of what happened last summer. ; Sebastian Amoruso as Johnny, Margot's gay best friend who has a special connection with Allison. He is part of what happened last summer. ; Fiona Rene as Lyla, a police officer who carries out the investigation of the murders and is connected to Bruce ; Cassie Beck as Courtney, Riley's mother, a somewhat violent woman who works at Ohana Restaurant and Lodging ; Brooke Bloom as Clara, a mysterious woman who seems to have a connection with the twin's mother. She knows what happened last summer. 
Title: I Know What You Did Last Summer (franchise)
Content:  The murderous fisherman with a hook stalks the two surviving teens, Julie James and Ray Bronson who left him for dead. Despite Julie's warnings, her friends do not believe her until it is too late, and the fisherman begins a second murder spree at a posh island resort in the Bahamas.
Title: I Know What You Did Last Summer (franchise)
Content:  I Know What You Did Last Summer is a horror film franchise consisting of three slasher films and one television series, loosely based on the novel of the same name by Lois Duncan. The first installment was written by Kevin Williamson, directed by Jim Gillespie, and released in 1997. The first two installments star Jennifer Love Hewitt, Freddie Prinze Jr. and Muse Watson. In addition, the supporting cast includes: Sarah Michelle Gellar, Ryan Phillippe and Johnny Galecki in the first film, with Brandy, Mekhi Phifer and Matthew Settle in the second film.
Title: I Still Know What You Did Last Summer
Content:  I Still Know What You Did Last Summer is a 1998 slasher film directed by Danny Cannon and written by Trey Callaway. Jennifer Love Hewitt, Freddie Prinze Jr. and Muse Watson reprise their roles, with Brandy, Mekhi Phifer and Matthew Settle joining the cast. It is the second installment in the I Know What You Did Last Summer franchise. The film takes place one year after the events of its predecessor. I Still Know What You Did Last Summer received negative reviews and grossed $84 million on a budget of $24 million. It was shot in Mexico and California. It was followed by I'll Always Know What You Did Last Summer in 2006.
Title: I Know What You Did Last Summer
Content:  I Know What You Did Last Summer is a 1997 American slasher film directed by Jim Gillespie, written by Kevin Williamson, and starring Jennifer Love Hewitt, Sarah Michelle Gellar, Ryan Phillippe and Freddie Prinze Jr. It is loosely based on the 1973 novel of the same name by Lois Duncan and is the first installment in the I Know What You Did Last Summer franchise. The film centers on four young friends who are stalked by a hook-wielding killer one year after covering up a car accident in which they killed a man. The film also draws inspiration from the urban legend known as the Hook, and the 1980s slasher films Prom Night (1980) and The House on Sorority Row (1982). After having written Scream (released the year prior), Williamson was approached to adapt Duncan's source novel by producer Erik Feig. Where 
Title: I Know What You Did Last Summer
Content: Jennifer Love Hewitt as Julie James ; Sarah Michelle Gellar as Helen Shivers ; Ryan Phillippe as Barry Cox ; Freddie Prinze Jr. as Ray Bronson ; Bridgette Wilson as Elsa Shivers ; Anne Heche as Melissa "Missy" Egan ; Muse Watson as Ben Willis / The Fisherman ; Johnny Galecki as Max Neurick ; Stuart Greer as Officer 
Title: I Know What You Did Last Summer
Content:  I Know What You Did Last Summer has been referenced in various films and television series, and its central plot was parodied at length in the spoof film Scary Movie (2000). It was also spoofed in The Simpsons episode "Treehouse of Horror X" as "I Know What You Diddily-Iddily-Did", with Ned Flanders as the killer.
Title: I'll Always Know What You Did Last Summer
Content:  I'll Always Know What You Did Last Summer is a 2006 American direct-to-video slasher film. The film is the third installment of I Know What You Did Last Summer franchise, but does not have any of the cast returning from the first two installments, thus making it a standalone sequel to I Still Know What You Did Last Summer. The film instead takes the basic myth of the series and starts it over with a new set of characters. I'll Always Know What You Did Last Summer was released on DVD on August 15, 2006.
Title: I Still Know What You Did Last Summer
Content:  a body in the middle of the road. When Ray discovers the body is a mannequin, Ben appears and kills Dave with his hook. Ben then chases Ray in a truck, but Ray escapes and falls down a hill. The next morning, Julie, Karla, Karla's boyfriend, Tyrell Martin (Mekhi Phifer), and their friend, Will Benson (Matthew Settle), depart for the trip. The group arrives at the hotel in Tower Bay and checks in. That evening at the hotel's bar, Julie is singing karaoke when the words "I still know what you did last summer" roll onto the screen. Terrified, she runs back 
Title: I Still Know What You Did Last Summer
Content: Jennifer Love Hewitt as Julie James ; Freddie Prinze Jr. as Ray Bronson ; Brandy as Karla Wilson ; Mekhi Phifer as Tyrell Martin ; Matthew Settle as Will Benson ; Jennifer Esposito as Nancy ; Muse Watson as Ben Willis / The Fisherman ; Bill Cobbs as Estes ; Jeffrey Combs as Mr. Brooks ; Benjamin Brown as Darick the Dockhand ; Ellerine Harding as Olga ; John Hawkes as Dave ; Jack Black as Titus Telesco (uncredited) 

Question: who was the killer in the movie i know what you did last summer?
Answer: Ben Willis.