An Algonquin, Ill. man charged with sexually assaulting a minor is a blood relative of John Wayne Gacy, a convicted serial killer and rapist who targeted young men, many of them minors. But prosecutors, defenders and the judge presiding over his trial agree jurors don't need to know that detail.

The familial connection is "irrelevant" to the case, McHenry County state's attorney's criminal division chief told the Chicago Tribune. Even without that detail, the case against Kasper is complicated enough: in court Tuesday during the first full day of testimony, the alleged victim nervously recanted her claims, saying the assault had been a dream.

During the trial that began Monday, prosecutors alleged that Kasper assaulted a girl under the age of 13 between June and October of 2011, according to UPI.

Defense attorney Michael Barrett argued that the alleged victim gave "glaringly inconsistent" stories, and harbored anger against Kasper, who had dated her mother for years and lived with the family before having an affair, the Northwest Herald reports. Prosecutors say the victim was berated under questioning and encouraged to change her story.

Kasper is facing multiple charges of committing sex offenses against a child under 13, Fox Chicago reports.

Gacy was executed by lethal injection in 1994, but his impact on Illinois is still tangible. In October, the bodies of eight unidentified victims were exhumed to be analyzed with new DNA technology. See photos from that story below:

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  • Gacy Victims Exhumed

    This undated photo provided by the Cook County Sheriff's Department shows victims remains of serial killer John Wayne Gacy being exhumed by authorities. The Cook County Sheriff's Department last spring secretly exhumed the bones of the 8 victims who were never identified in the hopes that scientific tests that were not around between 1972 and 1978 when Gacy killed his 33 victims will make identification possible. (AP Photo/Cook County Sheriff's Department)

  • This undated photo provided by the Cook County Sheriff's Department shows buckets containing jaw bones and teeth of victims of serial killer John Wayne Gacy that were exhumed by authorities. The Cook County Sheriff's Department last spring secretly exhumed the bones of the 8 victims who were never identified in the hopes that scientific tests that were not around between 1972 and 1978 when Gacy killed his 33 victims will make identification possible. (AP Photo/Cook County Sheriff's Department)

  • This undated photo provided by the Cook County Sheriff's Department shows buckets containing jaw bones and teeth of victims of serial killer John Wayne Gacy that were exhumed by authorities. The Cook County Sheriff's Department last spring secretly exhumed the bones of the 8 victims who were never identified in the hopes that scientific tests that were not around between 1972 and 1978 when Gacy killed his 33 victims will make identification possible. (AP Photo/Cook County Sheriff's Department)

  • Police officials use a radar unit resembling a power lawn mower to scan an area near an apartment building in Chicago, Monday, Nov. 23, 1998, where they suspected more victims of serial killer John Wayne Gacy might have been buried. The building is where Gacy's mother used to live. Police announced that Monday's dig produced no human remains. (AP Photo/Stephen J. Carrera)

  • Grid patterns are drawn on the lawn Monday, Nov. 23, 1998, where Chicago police will begin excavating for more possible victims of serial killer John Wayne Gacy. The apartment building is where Gacy's mother used to live. (AP Photo/Charles Bennett)

  • A fence surrounds the yard of the apartment building where the mother of convicted serial killer John Wayne Gacy once lived Sunday, Nov. 22, 1998 in Chicago. Prompted by new evidence, police plan to begin digging Monday for more potential Gacy victims outside the brick apartment building on Chicago's Northwest Side. (AP Photo/Michael S. Green)

  • Serial killer John Wayne Gacy is shown in this 1978 photo. (AP Photo)

  • Photo: Cook County Sheriff's Office

  • Photo: Cook County Sheriff's Office

  • Gacy Victim Profiles

    The sheriff's office released a timeline of the Gacy murder investigation as well as their exhumation schedule. The following profiles are of the unidentified Gacy victims whose bodies were exhumed.

  • The sheriff's office released a timeline of the Gacy murder investigation as well as their exhumation schedule. These profiles are of the unidentified Gacy victims whose bodies were exhumed.

  • The sheriff's office released a timeline of the Gacy murder investigation as well as their exhumation schedule. These profiles are of the unidentified Gacy victims whose bodies were exhumed.

  • The sheriff's office released a timeline of the Gacy murder investigation as well as their exhumation schedule. These profiles are of the unidentified Gacy victims whose bodies were exhumed.

  • The sheriff's office released a timeline of the Gacy murder investigation as well as their exhumation schedule. These profiles are of the unidentified Gacy victims whose bodies were exhumed.