By Frances Robles | The New York Times

Alexa Negrón Luciano, transgender and homeless, walked the streets of Puerto Rico neighborhoods hunched over, with a long towel covering her jet-black tresses.

She was a well-known figure on Puerto Rico social media, where people frequently posted photos and comments mocking her as something of an oddball bag lady. .

On Sunday, the mockery turned deadly. Someone posted photos of Ms. Negrón being questioned by the police for supposedly peeping at another customer in a women’s bathroom at a fast-food restaurant, and the post went viral. Not 12 hours later, she was framed in the headlights of a car and shot to death amid a cackle of laughter — her final moments apparently also posted on social media.

At 27, Ms. Negrón became the latest example in a long legacy of violence against gay and transgender people in Puerto Rico.

“This is violence against women, without a doubt,” said Gov. Wanda Vázquez, describing the case as “sad, cruel and insensitive.” The governor, who is the former top prosecutor on the island, said the killing would be investigated as a hate crime.

Ms. Negrón’s death has become a flash point in a long-running debate about years of deadly attacks on gay and transgender people in Puerto Rico.

If the video is authentic, Ms. Negrón’s killers were comfortable enough to record themselves, a fact that community activists said underscores the impunity homophobic attackers feel when committing such crimes.

Even as public attitudes toward gay and transgender people have shifted globally, including in Puerto Rico, a small cadre of powerful conservative Christians on the island remain vocal about pushing back against moves to be more inclusive.

A project to conduct sensitivity training for the police got little traction, and a proposed gender-based curriculum for public schools was stopped in its tracks after opposition from religious leaders, said Thomas J. Bryan, a lawyer who worked on the issue for years before leaving for Florida after Hurricane Maria.

“The problem in Puerto Rico comes from a group of fundamentalist religious leaders who are against any progressive idea to resolve this kind of situation,” Mr. Bryan said. “This is what brings this intolerance out to the open, this kind of homophobia.”

The case has transfixed Puerto Rico, and caught notice on Wednesday on the presidential campaign trail. “I’m heartsick for Alexa and her loved ones,” Senator Elizabeth Warren of Massachusetts wrote on Twitter. “This epidemic keeps growing.”

Attention to the violence directed at gay people in Puerto Rico first occurred in the 1980s, when a man dubbed “Angel of the Bachelors” went on a killing spree, picking up gay men at bars and killing them. Police did not begin paying attention until a prominent journalist was stabbed to death in 1985, said Pedro Julio Serrano, a leading gay rights activist in Puerto Rico.

“These crimes are not only committed against the victim that is the target,” he said. “It’s a crime that sends a message to a whole sector of the community that they are in danger. It’s putting you in your place.”

The serial killer, Ángel Colón Maldonado, is serving a life sentence for three murders, but was suspected in 27 more cases. In a recent interview, he said he was guided by the Bible.

Fifteen years after the conviction, Puerto Rico legislators passed a hate crime bill, but prosecutors rarely use it, Mr. Serrano said.

In 2009, a gender nonconforming teenager named Jorge Steven López, who often wore women’s clothing, was decapitated, dismembered and set ablaze. The international condemnation that followed turned Mr. López into Puerto Rico’s version of Matthew Shepard, the gay Wyoming student whose death in 1998 triggered federal hate crime legislation.

Mr. López’s killer pleaded guilty after saying he committed the crime in a panic after picking Mr. López up for sex and discovering he was actually a man.

In the two years after that attack, at least 18 more gay and transgender people were killed in unrelated cases, prosecutors said at the time.

“After that we had like at least a dozen hate crimes, murders, for about five years in a row. And there were years that we had two dozen or more,” Mr. Serrano said. “There was like an epidemic, probably because more people would identify the victims as L.G.B.T., and the community was giving more information.”

Many of the killers were apprehended and prosecuted, although the cases were not handled as hate crimes, he said.

Religious leaders from around the island have spoken out against Ms. Negrón’s death. Another legislator who opposed some of the measures to protect the gay and transgender community, María M. Charbonier, condemned Ms. Negrón’s killing but suggested that transgender people should stick to the bathrooms that match their anatomy.

“I am a woman,” she said in a radio interview. “I do not enter men’s bathrooms.”

At least 26 transgender or gender nonconforming people were killed in 2019 across the United States, the vast majority of them black, the Human Rights Campaign said in a report released in November.

Ms. Negrón’s body was found early Monday on the side of the road in Toa Baja, about 15 miles west of San Juan, police said.

Police had questioned her at 5:15 p.m. the previous day after someone called police from a local McDonald’s, saying that Ms. Negrón had crouched under the bathroom door with a mirror to spy on women in the women’s restroom. When the police arrived, the person who had called said she was not interested in pressing charges, said Capt. Ricardo Haddock of the Puerto Rico Police investigations unit.

When police questioned her, Ms. Negrón gave her name as Neulisa Luciano Ruiz.

Then at 3:50 a.m. on Monday, police received an anonymous tip about a body on the side of the road about a mile from the McDonald’s. It was Ms. Negrón, and she had been shot several times in various parts of her body, Capt. Haddock said.

He said the police cannot categorize the death as a hate crime until a motive is clearly established. He said tips are being investigated, but police have not identified any possible assailants.

“The video is being analyzed. We are waiting for certification to determine whether it is genuine,” he said. “It does appear to be real.”