A San Antonio man accused of making threats in July against a Florida convention of young conservative activists was arrested on Sunday.

Alejandro Richard Velasquez Gomez, 19, was arrested on August 21 for reportedly threatening on social media to carry out a mass attack on the Turning Point USA Student Action Summit held from July 22 through July 24 in Tampa.

Turning Point USA is a non-profit organization that advocates for conservative activism on high school, college, and university campuses.

According to FBI agents, Velasquez allegedly posted a message to Instagram on July 22, when the convention began, saying that day would be “the day of retribution” as he would enact “revenge” on “all of humanity.”

Tampa police took the threat seriously and obtained an arrest warrant.

Velasquez was arrested on July 22 in San Antonio and charged with sending written or electronic threats to kill, injure, or conduct a mass shooting or an act of terrorism.

A criminal complaint filed in a San Antonio federal court alleged that Velasquez bought a plane ticket from Austin to Tampa on July 22. However, he canceled the ticket the night before his flight.

While it is unclear why the event was allegedly targeted, agents claimed that they believed Velasquez planned an attack similar to Elliot Rodger’s attack in 2014.

The Hollywood director’s son had killed students and injured over a dozen others near the University of California, Santa Barbara, before fatally shooting himself.

The FBI made their conclusion on Velasquez’s alleged plan based on his Instagram post, in which he was pictured sitting in a car.

Investigators claimed the post echoed a video by Rodger in which he promoted the “incel movement,” a radical online community of men who call themselves “involuntary celibates” and “anti-feminists.”

Rodger had posted the video to Youtube the day before his attack, speaking of life as a 22-year-old virgin and the women who rejected him.

“Tomorrow is the day of retribution,” he reportedly said, according to New York Times. “The day I will have my retribution against humanity. Against all of you.”

After Velasquez’s arrest, authorities allegedly found images considered to be child pornography on his phone. He was subsequently charged with possession of child pornography.