01:03 - Source: CNN
What is a hate crime?
CNN  — 

In the first case of its kind, a Mississippi man pleaded guilty to a federal hate crime Wednesday for murdering his ex-girlfriend because she was transgender.

Joshua Vallum, 29, knew Mercedes Williamson was a transgender teenage girl when they began dating, the US Justice Department’s Civil Rights Division said.

Vallum killed her because she was transgender, making him eligible for prosecution under the 2009 Matthew Shepard and James Byrd Jr., Hate Crimes Prevention Act, named for two of the country’s most infamous hate crimes.

The federal law criminalizes violence based on race, religion, gender, sexual orientation or gender identity. Vallum’s prosecution is the first to involve a victim targeted for being transgender, the Justice Department said.

“Our nation’s hate crime statutes advance one of our fundamental beliefs, that no one should have to live in fear because of who they are,” US Attorney General Loretta Lynch said in a statement.

“Today’s landmark guilty plea reaffirms that basic principle, and it signals the Justice Department’s determination to combat hate crimes based on gender identity.”

The news comes in the deadliest year ever for transgender people. As of November, the deaths of 26 transgender people were reported, more than any other year, according to GLAAD and other advocacy groups. Some questioned the significance of the prosecution, or the extent to which such laws actually prevent or deter hate crimes.

The number of reported hate crimes based on gender-identity since the FBI started collecting related data.

Vallum, a member of the Almighty Latin Kings and Queens Nation crime gang, kept her gender identity a secret. The two broke up in 2014 and had no contact until May 2015, when Vallum decided to kill her.

A consensual relationship turns deadly

A friend of his had learned that Williamson was transgender. Vallum feared reprisals from other Latin Kings members if they found out he was in a consensual sexual relationship with a transgender woman, the Justice Department said, citing statements Vallum made as part of his guilty plea.

After luring the 17-year-old into his car under false pretenses, he assaulted her and stabbed her with a pocket knife. As she tried to flee he stabbed her repeatedly and used a hammer to deliver the deadly blows, the Justice Department said.

Vallum initially claimed he killed Williamson in a panic after learning she was transgender. In his guilty plea Wednesday, he admitted to lying about the circumstances surrounding her death.

He would not have killed Williamson if she was not transgender, he admitted in his plea.

Vallum previously pleaded guilty in state court to murdering Williamson in George County, Mississippi, and was sentenced to life in prison. Because Mississippi does not have a statute that protects people from bias crimes based on gender identity, the federal government was able to bring federal hate crime charges.

Hate crimes reported in 2015

A disheartening landmark

The prosecution drew mixed reaction from civil rights groups.

Despite the circumstances, many lauded the prosecution, saying it sets an important precedent for using hate crime laws to protect gender identity.

“It sends a message, especially to the LGBT community, that the federal government will use this law when they are victims of crime,” said Richard Saenz, staff attorney for Lambda Legal. “For too long LGBT people have been ignored and violence against them has been ignored and they’ve felt that crimes against them will never be taken seriously.”

Still, it’s a disheartening milestone, one that’s based in problems that laws alone can’t fix.

“It is important to note that our criminal justice system needs reform, and that simply adding new statutes that add to our already over-large prison population is insufficient to get at the root of the problem,” said Jillian Weiss, executive director of the Transgender Legal Defense & Education Fund.

“We must come together in our schools and churches and government halls to teach that prejudice is unacceptable.”

Others said it would do nothing to prevent future crimes.

“Enhanced sentencing does not bring about the core values and educational shift needed at interpersonal and community levels to address gender identity-based violence. More efficient interventions may include community-created safety alternatives and restorative processes,” said Flor Bermudez with the Transgender Law Center’s Detention Project.

“Hate crime laws do nothing to ensure the safety of transgender people, since they don’t address the root cause of the problem. To the contrary, hate crime laws use criminalization and enhanced punishment in a way that ultimately only expand the criminal system that already disproportionately targets transgender women of color. “

CNN’s Dani Stewart contributed to this report.