(CNN)A man accused of plotting a terrorist attack at an Ohio bar with his girlfriend was sentenced to six years in prison Tuesday, federal prosecutors announced.
Vincent Armstrong, 24, previously pleaded guilty to charges stemming from his participation in the plot. His girlfriend, Elizabeth Lecron was sentenced to 15 years in prison in November.
"This defendant admitted to helping plot and plan a mass-casualty attack in Toledo," US Attorney of the Northern District of Ohio Justin Herdman said. "His sentence reflects the seriousness of the charges against him and should serve as a reminder to all who live in our District and beyond - we will never stop working to protect our families, friends and neighbors."
According to the USAO, Lecron and Armstrong were "immersed" in an online group called the "True Crime Community," which "fixated and lionized mass murderers and posted extremely graphic images, videos, and sayings."
Lecron would routinely post about the gunmen in the 1999 Columbine High School shooting, in which 13 people were killed, and Dylann Roof, who killed nine people at a historically black church in Charleston, South Carolina, in 2015, the USAO said in an August news release.
In August 2018, the couple took a trip to visit sites linked to the Columbine High School shooting, the USAO said. Lecron also wrote "numerous letters" to Roof, according to the USAO.
The couple talked about carrying out a mass murder in the Toledo area, the USAO said, calling the attack "D-Day." The couple bought guns and went to the shooting range to practice for the attack, and purchased components to construct pipe bombs.
They wrote down their plans in personal journals, the USAO said. In hers, Lecron wrote, "D-Day will be my salvation." Upon executing a search warrant at the couple's home, investigators found an AK-47, two shotguns, two handguns and ammunition, the USAO previously said.
"Vincent Armstrong's sentence will ensure he remains safely away from the public for some time," FBI Special Agent in Charge Eric Smith said. "He and his fellow conspirator, Elizabeth LeCron, planned to attack and murder their fellow citizens for no other reason than their infatuation with violence. The FBI once again applauds the public for bringing LeCron and Armstrong's plans to the attention of law enforcement."