Luigi Mangione violated the “special treatment” he was afforded for his last court appearance when handwritten notes were concealed inside a pair of argyle socks he was allowed to wear, New York City prosecutors said Wednesday in a new court filing.

Mangione, who is accused of gunning down United Healthcare CEO Brian Thompson in December, was given special accommodations for his “fashion needs” when he was allowed to change out of his jail-issued clothing before his Feb. 21 court appearance, according to the filing.

The defense team gave a court officer a bag of clothes, which included a new pair of argyle socks wrapped around cardboard, the filing said.

“Secreted in the cardboard were two personal heart-shaped notes, one addressed to an unknown person named ‘Joan’ and the other to Luigi stating in part ‘know there are thousands of people wishing you luck,'” the Manhattan district attorney’s office said.

“In spite of this, the defendant was permitted to wear the argyle socks, which he first changed into and later changed out of because he felt that ‘they did not look good,'” prosecutors said.

Mangione ended up appearing sock-less at the court appearance, with shackles around his ankles.

“Fortunately, the items smuggled were handwritten notes and not contraband capable of harming the transporting officers,” prosecutors noted.

The sartorial detail was included in a filing that responded to defense accusations that prosecutors withheld grand jury witness testimony and copies of electronic devices seized upon Mangione’s arrest, in violation of discovery obligations.

Prosecutors conceded they have not provided the testimony of civilian witnesses before the grand jury because they “constituted a fraction of the testimony before the Grand Jury,” comprising four of the 23 witnesses called. Otherwise, the DA’s office said there have been ample discovery disclosures to the defense.

Prosecutors also said in Wednesday’s court filing that Mangione does not need his own “specially formulated laptop” in jail because he “fails to show a necessity” to receive one.

Mangione’s attorneys asked that he be provided with a laptop “modified to the detention center’s regulations” so he can view videos, photos and other evidence.

“Without the laptop, which allows Mr. Mangione to review discovery outside the presence of counsel, there are not enough visiting hours that would allow the defense to view all discovery with the defendant (including thousands of hours of video) and also meet the Court’s current motion schedule,” the defense said.

Few inmates at the Metropolitan Detention Center in Brooklyn are given laptops.

Prosecutors said Mangione “has ample access to desktop computers” that he can use to review evidence, conduct legal research, send emails and draft motions.

“Ironically, the defense repeats at every opportunity that defendant is being treated differently than other defendants similarly situated. Yet, that’s precisely what the defense seeks — special treatment for defendant, without circumstances that warrant it,” Assistant District Attorney Joel Seidemann said.

On Dec. 4, Mangione allegedly shot and killed Thompson in a premeditated attack outside a Hilton hotel in Midtown Manhattan as the CEO headed to an investors conference.

According to a newly disclosed court document, the backpack Mangione was carrying when he was arrested in Altoona, Pennsylvania, five days after the murder was full of items that could suggest he intended to remain on the run and, possibly, kill again.

The backpack had a gun, a Glock magazine, 9 mm cartridges and a silencer, along with a knife, phone charger, duct tape, passport, zip ties, clothes, a computer and handwritten notes, the automatic discovery form said.

Authorities also found receipts for items purchased at a CVS and for registration at a New York City hostel under the name Mark Rosario, which matches the name on a fake New Jersey driver’s license Mangione allegedly carried.

Prosecutors extracted data from devices linked to Mangione, including a Motorola cellphone he allegedly dropped while fleeing, the document said.

Mangione has pleaded not guilty to state charges.

He has not yet entered a plea to federal charges. One of the federal charges, murder through use of a firearm, makes Mangione eligible for the death penalty if convicted.

He is due back in court on April 18.