UnitedHealthcare CEO murder suspect Luigi Mangione’s defense attorney in Pennsylvania is arguing that his DNA obtained from a snack that Altoona police gave him after detaining him should not be allowed in court, according to court filings.

Mangione, 26, is charged with first-degree murder in furtherance of an act of terrorism, stalking and a slew of other state and federal charges in both New York and Pennsylvania for allegedly gunning down UnitedHealthcare CEO Brian Thompson, a married father of two, on a sidewalk in Manhattan in December 2024.

In court documents filed last week, Mangione’s Pennsylvania criminal defense attorney, Thomas Dickey, argued that Mangione’s constitutional rights were violated during his detention and arrest at a McDonald’s in Altoona, where Mangione allegedly fled by bus after Thompson’s murder.

Dickey is arguing that because Mangione was detained and arrested illegally, his DNA collected from food that Altoona police gave him at the station was obtained unlawfully and should not be permitted as evidence in court.

The NYPD released a still image from surveillance video, showing him pulling his face mask down and smiling while flirting with a clerk at the check-in of the Manhattan hostel where police say he stayed for the murder. It went viral and immediately attracted a wave of support online for the accused killer.

The suspected gunman in UnitedHealthcare CEO Brian Thompson’s murder, believed to be Luigi Mangione, is seen flirting with a hostel employee on surveillance footage before the Dec. 4 shooting. (NYPD)

The suspect allegedly fled the scene of Thompson’s murder, rode a bike to a bus station and took a bus to Altoona, where he was ultimately identified and arrested.

Mangione is originally from Maryland and recently lived in California and Hawaii. He graduated as valedictorian from the Gilman School, a private all-boys high school in Baltimore, in 2016.

Mangione went on to receive his bachelor’s and master’s degrees in computer science from the University of Pennsylvania in 2020.

Fox News Digital’s Michael Ruiz and Jordan Early contributed to this report.