Question: Which American man claimed the song "Exit" by U2 influenced him to murder Rebecca Schaeffer?

full_context: Document 1: Dennis Rader: Dennis Lynn Rader (born March 9, 1945) is an American serial killer who murdered ten people in Sedgwick County, Kansas between 1974 and 1991.
Document 2: Rebecca Schaeffer: Rebecca Lucile Schaeffer (November 6, 1967 – July 18, 1989) was an American model and actress.
Document 3: Exit (U2 song): "Exit" is a song by rock band U2. It is the tenth track on their 1987 album "The Joshua Tree". "Exit" was developed from a lengthy jam that was recorded in a single take and edited down to a shorter arrangement. The lyrics, which portray the mind of a serial killer, were inspired by lead singer Bono's reading of Norman Mailer's 1980 novel "The Executioner's Song", and other related works. In his trial for the murder of Rebecca Schaeffer, Robert John Bardo used "Exit" as part of his defence, claiming the song had influenced his actions.
Document 4: Randy Roth: Randy Roth is a convicted murderer and thief from Washington. He was convicted of the 1991 murder of his fourth wife, Cynthia Baumgartner Roth. He was suspected but never tried for murdering his second wife, Janis Roth, in 1981. In both deaths he was the only witness, he claimed the activity that led to the death was the idea of his deceased wife, and the bodies were cremated as quickly as could be arranged. He was also convicted of stealing in the form of defrauding insurers and the Social Security Administration and was sentenced to one year for theft and 50 years for first degree murder in 1992. At least two true crime books are based on Roth's crimes, "A Rose for Her Grave" by Ann Rule and "Fatal Charm" by Carlton Smith.
Document 5: Jacob D. Robida: Jacob D. Robida (June 13, 1987 – February 5, 2006) was a Massachusetts teenager who attacked three patrons at a New Bedford gay bar on February 2, 2006. He fled the state and drove to Charleston, West Virginia, where he kidnapped Jennifer Rena Dunlap Bailey and drove southwest. He was stopped by Gassville, Arkansas Police Officer James W. Sell at the Brass Door Restaurant parking lot on the afternoon of February 4, 2006 for an apparent traffic violation. Robida shot and killed Sell and fled east. He turned onto Arkansas Highway 201 headed south and continued to Arkana, where he fired at Arkansas State Police Sgt. Van Nowlin. Deputies from the Baxter County Sheriff's Office had a spike strip deployed a short distance away. Robida drove over the spike strip, flattening both front tires on his Pontiac. He continued to Arkansas Highway 5, where he turned south and drove into the small town of Norfork. In the middle of town he lost control of the car due to the front tires, spun out, and hit two parked vehicles. He then shot Bailey, his kidnap victim, in the head with a Ruger 9mm semi-automatic pistol, killing her instantly. Police then opened fire on Robida. He shot himself in the right side of the head.
Document 6: One (U2 song): "One" is a song by Irish rock band U2. It is the third track from their 1991 album "Achtung Baby", and it was released as the record's third single in February 1992. During the album's recording sessions at Hansa Studios in Berlin, conflict arose between the band members over the direction of U2's sound and the quality of their material. Tensions almost prompted the band to break up until they achieved a breakthrough with the improvisation of "One"; the song was written after the band members were inspired by a chord progression that guitarist the Edge was playing in the studio. The lyrics, written by lead singer Bono, were inspired by the band members' fractured relationships and the German reunification. Although the lyrics ostensibly describe "disunity", they have been interpreted in other ways.
Document 7: The Joshua Tree: The Joshua Tree is the fifth studio album by Irish rock band U2. It was produced by Daniel Lanois and Brian Eno, and was released on 9 March 1987 on Island Records. In contrast to the ambient experimentation of their 1984 release, "The Unforgettable Fire", the band aimed for a harder-hitting sound within the limitation of conventional song structures on "The Joshua Tree". The album is influenced by American and Irish roots music, and through sociopolitically conscious lyrics embellished with spiritual imagery, it contrasts the group's antipathy for the "real America" with their fascination with the "mythical America".
Document 8: Love Is Blindness: "Love Is Blindness" is a song by rock band U2, and the twelfth and final track on their 1991 album "Achtung Baby". The song was written on piano by lead singer Bono during the recording sessions for U2's 1988 album "Rattle and Hum". Originally intending to give the song to singer Nina Simone, the band decided to keep it for "Achtung Baby" after playing it together. Thematically, the song describes a failing romance, mixing personal themes with imagery of metaphorical acts of terrorism. During the recording sessions for "Achtung Baby", guitarist the Edge separated from his wife, Aislinn O'Sullivan. The separation had a major effect on the development of the song; Bono said that the ending guitar solo was a cathartic experience for the Edge, as he snapped several guitar strings during the recording.
Document 9: Robert John Bardo: Robert John Bardo (born January 2, 1970) is an American man serving life imprisonment without parole after being convicted in October 1991 for the murder of American actress Rebecca Schaeffer on July 18, 1989, whom he had stalked for three years beforehand.
Document 10: Songs of Experience (U2 album): Songs of Experience is the upcoming fourteenth studio album by Irish rock band U2. It will be released on 1 December 2017. The album is intended to be a companion piece to U2's previous record, "Songs of Innocence" (2014). Whereas its predecessor explored the group members' adolescence in Ireland in the 1970s, "Songs of Experience" thematically will be a collection of letters written by lead vocalist Bono to people and places closest to his heart. The personal nature of the lyrics reflects a "brush with mortality" that he had during the album's recording. The band collaborated with a variety of producers for the record, including Steve Lillywhite, Ryan Tedder, Jacknife Lee, Jolyon Thomas, and Andy Barlow.
Document 11: Barry George: Barry Michael George (born 15 April 1960, also known as Barry Bulsara) is a British man who was wrongly convicted on 2 July 2001 of the murder of British television presenter Jill Dando.
Document 12: Black Sun Ensemble: Black Sun Ensemble is a Tucson, Arizona, US–based psychedelic rock band, led by Jesus Acedo that was formed in the mid-1980s. The initial albums garnered rave reviews from Rolling Stone and several of the independent music journals of the time. Black Sun Ensemble opened for Camper Van Beethoven on the "Key Lime Pie" tour in 1989 to appreciative audiences across North America. Infamous circumstances surrounding their Geffen Records showcase in Los Angeles lead to the quiet intervention of Paul McCartney to get certain members and their entourage out of custody- a tarot card was involved, but any more may detail may arouse the attorneys! (based on statements from Jesus Acedo & Duane Norman). Additionally, the bloody death of a goat in the audience at the 1994 Burning Man festival lead to widespread public outcry and condemnation from animal rights group PETA. The band was forced underground and splintered, reformed and fell into hiatus due to extenuating circumstances and the mental illness of Jesus Acedo. Mickey Rourke, a close friend to Jesus Acedo at the time, was urged by friends and family to visit Acedo in his dreams embodying the dark angel, compelling him to resume writing. This was the inspiration for the song, "Murder" (showcased on the October 29, 2015 episode of Shonda Rimes' ABC hit show How to Get Away with Murder). Furthermore, if Mickey Rourke bestows a mood ring upon you, you take it.
Document 13: Lindsay Robert Rose: Lindsay Robert Rose is an Australian contract killer from New South Wales, currently serving five consecutive sentences of life imprisonment without the possibility of parole for the murder of 5 people between 1984 and 1994.
Document 14: Zoo Station (song): "Zoo Station" is a song by Irish rock band U2. It is the opening track from their 1991 album "Achtung Baby", a record on which the group reinvented themselves musically by incorporating influences from alternative rock, industrial, and electronic dance music. As the album's opening track, "Zoo Station" introduces the band's new sound, delivering industrial-influenced percussion and several layers of distorted guitars and vocals. Similarly, the lyrics suggest the group's new intents and anticipations. The introduction, featuring an "explosion" of percussion and a descending glissando for a guitar hook, was meant to make the listener think the album was mistakenly not U2's latest record or that their music player was broken.
Document 15: The Wanderer (U2 song): "The Wanderer" is the tenth and final track from U2's 1993 studio album, "Zooropa". It is one of the few U2 songs without Bono on lead vocals, instead featuring country singer Johnny Cash. The Edge provides harmonising backing-vocals throughout the song, but the country style howl at the end is by Bono.
ground_truth: Robert John Bardo