A former federal prosecutor said the Trump administration is using the Luigi Mangione case to “send a message” in the first 100 days through its potential use of the death penalty.

Mangione pleaded not guilty to federal charges of stalking, murder through a firearm, and other firearms offenses during an arraignment hearing on Friday. He’s accused of killing UnitedHealthcare CEO Brian Thompson in December outside a Hilton hotel where an annual shareholder meeting was scheduled to take place.

Federal prosecutors indicated in a Thursday night filing that they intend to seek the death penalty against Mangione. Prosecutors argued that Mangione “intentionally” targeted and killed Thompson because he was the CEO of a major health insurance company.

“Mangione elected to murder Thompson under these circumstances to amplify an ideological message, maximize the visibility and impact of the victim’s murder, and to provoke broad-based resistance to the victim’s industry,” prosecutors wrote.

UnitedHealthcare CEO Brian Thompson was killed on Dec. 4, 2024. (AP Photo/UnitedHealth Group)

Before leaving office in January, Biden commuted the death sentences of 37 out of 40 inmates who will now face life in prison without the possibility of parole.

Trump indicated in December that he would direct the Department of Justice to resume using the death penalty.

“As soon as I am inaugurated, I will direct the Justice Department to vigorously pursue the death penalty to protect American families and children from violent rapists, murderers and monsters,” Trump said at the time.

Outside the courthouse during Friday’s arraignment, a large group of Mangione supporters gathered and held signs that read “No death for Luigi Mangione,” “Free Luigi” and “Luigi before fascists.”

Supporters of Luigi Mangione gather outside federal court in Manhattan, Friday, April 25, 2025. The 26-year-old is facing murder charges for the alleged assassination of UnitedHealthcare CEO Brian Thompson. (David Dee Delgado for Fox News Digital)

Artist Scott LoBaido unveils a sculpture meant to represent Luigi Mangione in an electric chair outside federal court in Manhattan, Friday, April 25, 2025. The 26-year-old Mangione is potentially facing the death penalty as he pleads not guilty to murder charges for the alleged assassination of UnitedHealthcare CEO Brian Thompson. (David Dee Delgado for Fox News Digital)

One person, however, showed his distaste toward Mangione by bringing an electric chair with a skeleton, depicted as Mangione, sitting on it. The man who brought the chair held a sign reading “F–k Luigi.”

Fox News Digital’s Andrea Margolis contributed to this report.