It was about 8 p.m. on Feb. 2, 2012, and JaParker Deoni Jones had just left her mother’s place and was waiting at a nearby bus stop to catch a ride home.

As she sat at the bus shelter, someone plunged a knife into the side of her head and ran off. A passer-by who thought he had witnessed a mugging gave chase, but was unable to catch the assailant. Jones, 23, died minutes later at a nearby hospital.

About two weeks after the killing, police arrested Gary Montgomery, a man who was a stranger to Jones and who was seen on security video cameras sitting next to her at the bus stop.

Montgomery, 60, is on trial in D.C. Superior Court, where prosecutors have been presenting evidence to make a case that he is guilty of first-degree murder. The defense contends that their client is innocent and that police arrested the wrong man.

The motive remains unclear, but Jones’s family is convinced she was targeted because she was transgender.

Jones, who worked at a sandwich shop and a hair salon, was the oldest child, with two younger sisters. At 16, Jones began living as a female, her mother, Judean Jones, said in a recent interview. It was then, Judean Jones said, that she began to worry that the teen’s transgender status could make her a target of hate and violence.

“I always told her to be careful. I told her there would be people out there who won’t like you just because of who you are,” Judean Jones said.

Although prosecutors say it is not clear whether Montgomery even knew Jones was transgender, the killing pushed her mother and stepfather to become advocates for the transgender community. In 2013, then-Mayor Vincent C. Gray signed the JaParker Deoni Jones Birth Certificate Equality Act, which makes it easier for transgender individuals to change the gender on their birth certificates.

The trial, entering its third day of testimony on Tuesday, arrived in court as attention to violence against transgender women has resurfaced nationwide. Late last month, a stand-up comedian on a popular New York-based morning radio program, “The Breakfast Club,” joked that if a sexual partner turned out to be a transgender woman, he would want to kill her if she hadn’t told him beforehand. The comments were denounced by transgender advocates and celebrities on social media.

Jones’s family also was outraged. “It’s horrendous for anyone to make a statement like that,” said Jones’s stepfather, Alvin Bethea. “It just enables people to hurt trans persons. Or even kill them.”

Prosecutors said Jones and Montgomery came upon each other by chance on that February night. Security camera footage shows Montgomery, who has a history of drug use, walking to the bus stop in the 4900 block of East Capitol Street NE.

JaParker Deoni Jones is shown in this photograph released by the U.S. attorney's office. Jones, a 23-year-old transgender woman, was killed at a D.C. bus stop in 2012. ( U.S. attorney's office)

During an on-camera interview with homicide detectives, he repeatedly described Jones as “the pretty lady.”

Three people identified Montgomery as being at the bus stop before Jones was killed, prosecutors told the jury.

One witness, Attalah Gabriel, 30, testified that she sat next to the two of them and noticed that Montgomery kept staring at Jones with his eyes widened. At one point, Gabriel said, Jones turned away and Montgomery moved closer to her, still staring. But no one ever said anything, she testified. Gabriel also recalled an odor of marijuana, although she did not see anyone smoking.

“He kept staring at her and she kept ignoring him, looking at her phone instead,” Gabriel testified. “She was visibly uncomfortable.”

Gabriel said she sat on the bench for about five minutes before leaving to walk to the nearest Metro station. Gabriel described the man at the bus stop as being around 30 years old. Montgomery was 55 at the time.

Another witness, Jermaine Jackson, 41, testified that he and a friend had stopped at a traffic light in front of the bus stop when they saw a man appear to strike Jones. Jackson said they went to check on her and then saw the knife in her head.

Jackson said that he chased the attacker but that person got away. In court, he was not able to identify Montgomery as the man he followed.

“Gary Montgomery ran from the scene as Ms. Jones lay dying at the cold concrete bus shelter on East Capitol Street that provided absolutely no shelter from him,” Assistant U.S. Attorney David Gorman told the jury.

The defense questioned the strength of the evidence. There was no DNA from Montgomery found on Jones’s body or the knife. No fingerprints. A coat and a jacket were found at the bus stop but were not linked to Montgomery.

“Mr. Montgomery is innocent. He did not kill JaParker Deoni Jones,” argued Monica Douglas, one of Montgomery’s public defenders. “This case is built on assumptions, speculations and shortcuts, and does not rely on any evidence. Mr. Montgomery was not there when she was stabbed.”

The case has taken more than five years to make it to trial after an extended back-and-forth as to whether Montgomery was competent to stand trial. Psychiatrists at St. Elizabeths Hospital, the District’s psychiatric facility, said Montgomery suffered from mental illness, including schizophrenia. Judge Lynn Leibovitz determined that the case could go forward.

Waiting for a resolution has been stressful, Jones’s family said. The family also said they wished prosecutors had added a hate-crime component to the charges.

“He sat on the bus bench and stared at my daughter. Stared in her face,” Judean Jones said. “He knew she was transgender. And that’s why he killed her.”