Luigi Mangione Fan-Made Shirts, Cups, Christmas Ornaments Surge on Etsy

The man accused of fatally shooting the UnitedHealthcare CEO is being celebrated by a portion of the country ... and now some are trying to make a buck off that twisted admiration.

Here's the deal ... Luigi Mangione was apprehended Monday ... and hours later, the Manhattan D.A. charged him with murder in the brazen December 4 fatal shooting of Brian Thompson.

Ever since the cold-blooded murder ... Mangione cultivated a large fan following of those who hate the health insurance industry -- so, it is not that big of a surprise that there's now merchandise celebrating the suspect.

From shirts to cups, from a Christmas ornament to even a mock-Time Person of the Year cover ... the morbid offerings continue to expand.

The bizarre admiration was stewing even before Mangione had been apprehended ... but it really took off after he was captured.

Mere minutes after the suspect was identified and internet sleuths found his socials ... admirers began posting Super Mario Bros. and "Sopranos" memes celebrating Mangione.

Even before Mangione had been identified ... morbid devotees held a look-alike contest in NYC, while others were buying the jacket they thought was the same as the one worn by the suspect.

Monday morning ... Mangione was busted in Altoona, Pennsylvania as he sat inside a McDonald's restaurant. A customer recognized Mangione from widely circulated wanted posters following Thompson's murder, and told an employee ... who then contacted local police, who responded and cuffed the suspect.

Authorities recovered the alleged pistol Mangione used in the murder and a 3-page manifesto he'd written railing against corporate America and the healthcare industry, according to police.