Bad Bunny performed on the The Tonight Show Starring Jimmy Fallon and made a bold statement about a trans woman's killing. (Screenshot via YouTube)

Puerto Rican trap singer Bad Bunny paid a subtle but touching tribute to a trans woman brutally killed Monday in a suspected crime described as “cruel and insensitive”.

Performing on The Tonight Show Starring Jimmy Fallon on Thursday, Bad Bunny, known off-stage as Benito Ocasio, shrugged off his dusty pink double-breasted blazer to reveal a simple slogan t-shirt.

“They killed Alexa,” the tee in Spanish, read, “not a man with a skirt.”

Trans, homeless and frequently sneered at online for her hunchbacked appearance and black tresses, Alexa Negrón Luciano was found dead Monday.

Framed in the headlights of a car and shot to death amid a cackle of laughter, Luciano’s final moments were uploaded in a vile video on social media. “You bet I am going to go and shoot him,” said one of her suspected killers in footage police confirmed was authentic.

Her death rippled across the community, yet many local outlets misgendered her in reports. The case echoed the brutal murder of gender-nonconforming teen Jorge Steven, found decapitated, dismembered and set ablaze in 2009.

Wow. Bad Bunny (@sanbenito) wore a skirt on the @FallonTonight with a sweater that read "they killed Alexa, not a man with a skirt"

Alexa was transgender woman in Puerto Rico ridiculed & killed, on her birthday, by murderers who videotaped the crime & posted it on social media. pic.twitter.com/i2iBAmdVK5 — David Begnaud (@DavidBegnaud) February 28, 2020

Bad Bunny sat down on the famous grey armchair with Fallon to discuss his new 20-song album, YHLQMDLG.

Dropping Saturday, the star also revealed the album’s new artwork as well as performing “Ignorantes”.

But during his costume change, he ditched his Supreme tee for one that sent a powerful statement against transphobes.

What happened to Alexa Negrón Luciano?

Luciano was killed in the early morning in the town of Toa Baja.

On Sunday, a local posted pictures of her being questioned by police for allegedly peeping at another customer in the women’s bathroom of a McDonald’s.

One showed her quietly tucking into her meal with a can of 7-Up beside her. She later gave her name to police as Neulisa Luciano Ruiz.

Just 12 hours later, she was dead. She was found on the side of a road around a mile from the fast-food restaurant.

Local law enforcement received a tip about her death at around 3.15am, where officers found she had been shot several times across her body.

'Alexa' was a transgender woman killed in Puerto Rico after social media posts accused her of peeping on people in a public bathroom. Police found no proof. The complainant didn't file charges after finding out Alexa was homeless. Despite that a narrative spread on social media. pic.twitter.com/xknfGH7HRD — David Begnaud (@DavidBegnaud) February 25, 2020

Police have not categorised Liciano’s killing as a hate crime as detectives wrestle to define a clear motive. Yet activists have argued that how her death was filmed demonstrates the impunity anti-LGBT+ people feel they have in Puerto Rico, where anti-discrimination laws are vastly lacking.

Elizabeth Warren: ‘I’m heartsick for Alexa and her loved ones.’

The 27-year-old was infamous around town. Ridiculed and mocked online for her appearance.

But how mockery turned deadly sparked outrage in Puerto Rico. A hashtag #SeLlamabaAlexa, or, ‘she was called Alexa’, went viral shortly after her death was announced by authorities.

A trans woman was murdered in Puerto Rico. It's appalling that local outlets are still referring to her as "a man dressed as a woman." Her name was Alexa, and she deserved better. Me dueles Puerto Rico! #SeLlamabaAlexa — Alicia Ramírez (@aramirezgar31) February 24, 2020

According to Metro Puerto Rico, members of her community knew her as “humble” and “noble”.

Her passing also drew attention from lawmakers, where governor Wanda Vázquez said at a press conference: “Everything points to this being a hate crime, and that’s how it will be treated.”

The former leading prosecutor added: “This is violence against women, without a death,” before describing Luciano’s death as “sad, cruel and insensitive”.

Democratic presidential candidate Elizabeth Warren, an outspoken trans ally, decried her death.

“I’m heartsick for Alexa and her loved ones,” the Massachusetts senator wrote on Twitter Wednesday.

I'm heartsick for Alexa and her loved ones. This epidemic keeps growing. We must use every tool we have to end it and protect trans women of color. #SeLlamabaAlexa https://t.co/Okka8fWyNW — Elizabeth Warren (@ewarren) February 26, 2020

“This epidemic keeps growing. We must use every tool we have to end it and protect trans women of colour.”