The 49-year prison sentence under federal hate crime law of a Mississippi man who killed a transgender Alabama woman represents a "glimmer of hope" for the nation's transgender community, activists said Tuesday.

The Monday sentencing of Joshua Vallum for the 2015 slaying of Theodore 17-year-old Mercedes Williamson was welcomed by LGBT community advocates in Alabama and beyond as is resulted from the first conviction under the federal Hate Crimes Prevention Act of a murderer who targeted a victim because of their gender identity.

But it is only a single victory in the ongoing battle for transgender rights and legal protections that shows no signs of abating.

"We have to have hope, and this is a hopeful sign, but it certainly shouldn't signal that people can sit back on their laurels," said David Dinielli, deputy legal director at the Southern Poverty Law Center's LGBT Rights Project.

The sentencing of Joshua Vallum for the 2015 slaying of Theodore, Alabama, 17-year-old Mercedes Williamson was welcomed by LGBT community advocates in Alabama and beyond as the first conviction under the federal Hate Crimes Prevention Act of a murderer who targeted a victim because of their gender identity.

But many cautioned that it does not signal that the Justice Department is necessarily going to take further measures to institute legal protections for transgender Americans.

"It's the first glimmer of hope since January," Kyle Pugh, director of the Magic City Wellness Center, which provides medical services to members of the LGBT community, said in the center's Birmingham offices Tuesday afternoon.

"Bear in mind, [the U.S. Justice Department is] saying it's not OK to kill someone in the street, but that it is OK to discriminate against them in housing, health care, employment and other areas."

In the wake of the sentencing, the Justice Department under U.S. Attorney General Jeff Sessions - a former U.S. Senator from Alabama - released a statement saying that it "reflects the importance of holding individuals accountable when they commit violent acts against transgender individuals."

Though some interpreted the Monday statement as a measure of support for the transgender community, Sessions has also taken steps to limit the rights of transgender people. In February, he backed a move by President Donald Trump's administration that withdrew protections instituted under President Barack Obama granting transgender public school students the right to use bathrooms that match their gender identity.

As such, Dinielli says this is not a major sign of forward momentum toward codifying the rights of transgender Americans, and that the show of support by Sessions could instead be little more than an effort to show how "tough on crime" he is.

"While we applaud the fact that the Department of Justice was involved in this case, we believe they have a broader obligation to ensure that transgender people are afforded all the dignities of the rest of us from birth to death," Dinielli said.

Still, Amanda Keller, director of the Magic City Acceptance Center and LGBTQ Program, said Vallum's sentencing under federal hate crime law is "encouraging" news for transgender people.

"This is the first time that that has happened at the federal level," she said. "I think it has a huge impact in the sense that it's finally a recognition that transphobic violence is unacceptable at the federal level."