Waukesha homicides: Nikita Casap to be sentenced for 2025 killings
Tatiana Casap and Donald Mayer; Nikita Casap in court on Jan. 8, 2026
WAUKESHA, Wis. - Nikita Casap will be sentenced on Thursday for killing his mother and stepfather inside their village of Waukesha home. FOX6 News plans to stream the hearing; it is scheduled to begin at 1:30 p.m.
Nikita Casap
In Court:
Prosecutors charged Casap, 18, with two counts of first-degree intentional homicide and eight other felonies. He pleaded guilty to the homicide charges, and as part of a plea deal, the district attorney's office dismissed the rest in January.
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During his plea hearing, Casap admitted that he killed his mother and also told a judge that he killed his stepfather. Prosecutors said they had a mountain of evidence against Casap.
WARNING: Details of this report may be disturbing to some readers. Discretion is advised.
Family photo: Nikita Casap, Tatiana Casap, Donald Mayer
Death investigation
The backstory:
Donald Mayer and his wife, Tatiana, were found dead in their Cedar Hills Drive home on Feb. 28, 2025. Prosecutors said Casap, who was 17 years old at the time, shot and killed them more than two weeks before they were found. Their bodies were severely decomposed.
According to court filings, Casap fantasized about killing his parents and himself. He had been in contact with a Russian speaker with a plan to try to flee to Ukraine before taking money, passports, a car and the family dog.
Law enforcement scene near Cider Hills and Heather, Waukesha
Casap did not leave Waukesha until Feb. 23. That is when prosecutors said he traveled through Illinois, Iowa, Nebraska, Wyoming and Colorado before getting arrested in rural northwestern Kansas. He was in his parents' SUV with the dog.
A criminal complaint said Casap was the driver, and a gun was seen "in plain view" on the passenger side floorboard. Driver's licenses of the deceased were also in the vehicle, as were unused ammunition and shell casings.
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Court filings said investigators found telegram messages in the days and weeks before the homicides between Casap and a Russian speaker, in which Casap asked, "…while in Ukraine, I'll be able to live a normal life? Even when it's found out I did it."
After the case was originally filed, prosecutors charged Casap with intimidating a witness. Waukesha County District Attorney Lesli Boese said the charge stemmed from what a classmate told police.
A Waukesha West High School student said Casap told her how he wanted to die by suicide and that despite a "happy childhood," he was planning to kill his parents. Casap allegedly told the girl, if anyone ever found out what he said to her, "it wouldn't end well."
Plot to assassinate Trump
Dig deeper:
An FBI investigation into Casap revealed a conspiracy to assassinate President Donald Trump in an effort to start a "political revolution," according to federal court documents FOX6 News obtained in April 2025.
As part of the homicide investigation, Casap's cellphone and other electronic devices were seized and searched. According to a search warrant, investigators uncovered material on Casap's cellphone related to "The Order of Nine Angles." The group is described in FBI documents as a "satanic cult" with "strong anti-Judiac, anti-Christian, and anti-Western ideologies" that claims to "incite chaos and violence."
Wisconsin teen named in warrant; expert on 'red flags,' extremism
Federal prosecutors said they found a plot to kill President Donald Trump on a Wisconsin teen's cellphone. An expert said there were "red flags."
The warrant also said Casap paid for, at least in part, "a drone and explosives to be used as a weapon of mass destruction to commit an attack." The killings of his mother and stepfather, according to the warrant, "appeared to be an effort to obtain the financial means and autonomy necessary" to carry out the plan.
An excerpt from an apparent manifesto specifically referenced Trump and said "getting rid of the president and perhaps the vice president" is "guaranteed to bring in some chaos." It later said: "Point being this manifesto is specifically for the attack that targets Trump."
The Source: FOX6 News reviewed documents from the Waukesha County District Attorney's Office, Wisconsin Circuit Court, U.S. District Court for the Eastern District of Wisconsin, Federal Bureau of Investigation and prior coverage of the case.