Teen charged with homicide after parents found dead in Wisconsin home

MILWAUKEE -- A Waukesha teenager has now been charged with killing his parents and hiding their bodies at their Wisconsin home last month.

The teen, 17-year-old Nikita Casap, was previously charged with felony counts of operating a motor vehicle without the owner's consent and theft of movable property following a welfare check at a Waukesha residence.

The welfare check led to the discovery of his parents dead in the home, identified as Tatiana Casap and Donald Mayer, mother and stepfather to Nikita Casap.

He is now facing new charges, including two counts for first-degree intentional homicide, two counts of hiding a corpse, theft of property over $10,000 and two counts of misappropriating ID to obtain money, the Waukesha County Sheriff's Office said Thursday.

The video in the player above is from a previous report.

Charges arose from an investigation that began on Feb. 28, when Waukesha County Sheriff's deputies responded to a home on Cider Hills Drive to conduct a welfare check.

The request for the check was made by Donald Mayer's mother from Massachusetts, prompted by concerns from Waukesha West High School regarding her grandson's prolonged absence from classes. Prosecutors stated he hadn't been to school in two weeks.

According to the criminal complaint, during the welfare check, deputies discovered the bodies of Casap and Mayer inside their residence. Their bodies were found in different rooms, both concealed under blankets and clothing.

Court records show that the mother was found with "a possible exit wound in the back near right shoulder, and found the stepfather with "an obvious wound to the back of victim's head."

The criminal complaint indicates that Mayer's mother initiated the welfare check after weeks without contact with her son and receiving "suspicious or weird text messages" purportedly from him on Feb. 23.

Mayer's sister last spoke with him on Feb. 18, when he mentioned feeling unwell and taking a break from social media.

Flock camera data indicated Donald Mayer's 2018 Volkswagen Atlas was last recorded on Feb. 23, and Tatiana Casap's vehicle on Feb. 11.

Deputies inside the residence saw Casap's vehicle was present, but Mayer's Volkswagen Atlas was not there.

A neighbor reported seeing Mayer's Volkswagen Atlas being driven by Nikita Casap alone on Feb. 23. Another neighbor noted the family's small black dog had not been seen recently.

Cellphone data placed Donald Mayer's and Nikita Casap's phones in Cheyenne, Wyoming.

Location data showed Nikita Casap's device leaving Waukesha on Feb. 24 and traveling through multiple states.

Police in Walcott, Iowa, confirmed video surveillance from Iowa 80 - The World's Largest Truckstop showed Mayer's Volkswagen Atlas with a single occupant, believed to be Nikita Casap, and a small black dog on Feb. 24.

Prosecutors say he also drove through Illinois, Nebraska, and Colorado before being arrested in Kansas.

On Feb. 28, at approximately 11:25 p.m., police in WaKeeney, Kansas, stopped Donald Mayer's Volkswagen Atlas. Nikita Casap was driving, and the family dog was in the vehicle. Casap was arrested in town, but near Interstate 70, after running a stop sign.

According to the complaint, a Smith & Wesson .357 Magnum firearm was observed in the vehicle, along with driver's licenses belonging to Mayer and Tatiana Casap, ammunition, and spent shell casings.

Investigators confirmed the stepfather owned a Smith & Wesson .357 Magnum, which was not found at the residence.

Nikita Casap was in custody in Trego County, Kansas earlier this month.

The Waukesha County Sheriff's Department has not yet released further details.

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ABC7 Chicago contributed to this report.