Question: Tim O'Kelly's character in the 1968 film "Targets" was loosely based on a mass murderer who killed multiple people are what school?

Context articles: Angst (1983 film)
Fritz Angerstein
Jeff Weise
The Stepfather (1987 film)
The Stepfather (2009 film)
Charles Whitman
Tim O'Kelly
Andrew Kehoe
Chrissie White (Emmerdale)
Omar Mateen

Angst (English: Fear) is a 1983 Austrian experimental psychological thriller film.
 Co-written and directed by Gerald Kargl with cinematography, writing, and editing by Academy Award-winner Zbigniew Rybczyński, it tells the story of a psychopath recently released from prison and is loosely based on real-life mass murderer Werner Kniesek.
 Though relatively obscure, the film has been highly acclaimed for its unconventional and innovative camera work and intense acting performances, particularly from lead actor Erwin Leder.
 The film was banned all over Europe for extreme violence in 1983.
Fritz Heinrich Angerstein (January 3, 1891 – November 17, 1925) was a German mass murderer, who killed 8 people at his home in Haiger, on December 1, 1924.
 The subject of a media spectacle, Angerstein, along with Fritz Haarmann and Peter Kürten, is considered one of the "three great mass murderer trials" of the Weimar Republic-era of Germany.
Jeffrey James Weise (August 8, 1988 – March 21, 2005) was an American teenage mass murderer and spree killer, who was a student at Red Lake Senior High School in Red Lake, Minnesota, located on the reservation of the Ojibwe people.
 He murdered nine people in a shooting spree on March 21, 2005.
 He killed his grandfather and his grandfather's companion before going to the reservation high school, where he murdered seven more people and wounded five others.
 He committed suicide before being captured by police.
The Stepfather is a 1987 American psychological horror thriller film directed by Joseph Ruben and starring Terry O'Quinn, Jill Schoelen and Shelley Hack.
 O'Quinn stars as Henry Morrison, an identity-assuming serial killer who remarries a widow with a teenage daughter.
 After previously killing his family and changing his identity, his killing spree continues after his stepdaughter becomes suspicious about him.
 It is loosely based on the life of mass murderer John List, although the plot is more commonly associated with slasher films of the era than a true story.
 The film was written by Donald E. Westlake, from a story by Westlake, Carolyn Lefcourt and Brian Garfield.
The Stepfather is a 2009 American horror thriller film and a remake of the 1987 horror film of the same title.
 The film was directed by Nelson McCormick and stars Penn Badgley, Dylan Walsh and Sela Ward.
 The original was directed by Joseph Ruben and shot from a script by Donald Westlake.
 The films are loosely based on the crimes of mass murderer John List (who died in prison custody on March 21, 2008 at the age of 82 before its release).
Charles Joseph Whitman (June 24, 1941 – August 1, 1966) was an American mass murderer who became infamous as the "Texas Tower Sniper".
 On August 1, 1966, he murdered his mother and wife in their homes, then went to the University of Texas at Austin where he shot and killed three people inside the university's tower.
 He then went to the tower's 28th-floor observation deck, where he fired at random for some 96 minutes, killing an additional eleven people and wounding thirty-one before being shot and killed by police.
 Sixteen people were killed in total; a 17th victim died in 2001 from injuries sustained in the attack.
Tim O'Kelly (born Timothy Patrick Wright, March 12, 1941 – January 4, 1990) was an American actor best known for playing the homicidal sniper Bobby Thompson in the Peter Bogdanovich cult film "Targets" (1968).
 He was cast because of his boy-next-door looks and his similarity in appearance to killer Charles Whitman, on whom the character was loosely based.
 O'Kelly also played Detective Danny "Danno" Williams in the pilot episode of "Hawaii Five-O", but was replaced by James MacArthur.
Andrew Philip Kehoe (February 1, 1872 – May 18, 1927) was an American farmer and treasurer of his township school board, notable as a mass murderer for killing his wife and 43 other people (including 38 children), and injuring 58 people by setting off bombs in the Bath School disaster on May 18, 1927.
 He committed suicide near the school by detonating dynamite in his truck, causing an explosion which killed several other people and wounded more.
 He had earlier set off incendiary devices in his house and farm, destroying all the buildings, as well as killing two horses and other animals.
Christine "Chrissie" White (also Sugden) is a fictional character from the British ITV soap opera, "Emmerdale", played by Louise Marwood.
 She made her first screen appearance on 23 October 2014.
 The character and casting was announced on 4 October 2014.
 The character was the fiance of established character Robert Sugden (Ryan Hawley), who announced the character to return to the series after five years.
 Her storylines have included: her turbulent relationship and later marriage to Robert; being caught up in a raid at Home Farm organised by Robert; defending her teenage son Lachlan White (Thomas Atkinson) when it is revealed that he sexually assaulted Alicia Metcalfe (Natalie Anderson); discovering that Robert has been having an affair with Aaron Livesy (Danny Miller); accidentally causing a helicopter crash which killed multiple residents; discovering that Lawrence White (John Bowe) is not her biological father; embarking on a relationship with Robert's adoptive brother Andy Sugden (Kelvin Fletcher); framing Andy for Lawrence's attempted murder when Lachlan shoots him after discovering that Andy had cheated on her; and her intense feud with her younger sister Rebecca White (Emily Head).
Omar Mir Seddique (November 16, 1986 - June 12, 2016), also known as Omar Mateen, was an American mass murderer who killed 49 people and wounded 58 others in a mass shooting at the Pulse gay nightclub in Orlando, Florida, on June 12, 2016, before he was killed in a shootout with the local police.
 It was both the deadliest shooting by a single shooter and the deadliest act of violence targeting LGBT people in United States history.