Nikolas Cruz at Broward County Jail. Photo: Miguel Guttierez/AFP/Getty Images

Nikolas Cruz, the 19-year-old gunman at the center of Wednesday’s school shooting that killed 17 people, is a member of the white supremacist group Republic of Florida (ROF), a spokesperson for the group claimed Thursday. Police in Tallahassee, where ROF is based, have not found a connection, but they are “still doing some work,” a spokesperson told the Tallahassee Democrat.

Jordan Jereb, a self-described “right-wing extremist nut,” told the Anti-Defamation League that Cruz traveled from his home in South Florida to train with the ROF near Tallahassee at least once. The ROF, which describes itself as a “white civil rights organization,” holds paramilitary drills for its members and has posted videos of them online.

“He probably used that training to do what he did yesterday,” Jereb told the Daily Beast.

Jereb told the Associated Press that the group had no prior knowledge of the attack. He did have some insight into a possible motive, though, saying that Cruz recently had “trouble with a girl.” He added that carrying out the shooting on Valentine’s Day may not have been a coincidence.

Some of Cruz’s former classmates at Marjory Stoneman Douglas High School confirmed to ABC News that Cruz had been seen with Jereb before and was known to participate in ROF marches.

The ADL first contacted Jereb after ROF members on 4Chan claimed that Cruz was a member of the group.