Sentencing takes place on January 30th. Barriss also faces another trial January 7th for involuntary manslaughter against Finch. Alleged co-conspirators Casey Viner and Shane Gaskill have pleaded not guilty and face a trial on January 8th.
Barriss is mainly known for a December 2017 incident where he made a false call to police as the result of a heated debate over a Call of Duty: WWII match between Gaskill and Viner. When Viner grew upset, he dared Barriss to make a swatting call against Gaskill -- and didn't realize that Gaskill had given him an old address. A police officer shot Finch, the new resident at the address, when he came to the door unaware of what was going on.
However, the charges are ultimately the culmination of a series of incidents. On Twitter, Barriss had taken credit for bomb threats to the Dallas Convention Center, a Florida high school and the FCC's net neutrality repeal vote. We wouldn't expect the court to be lenient on Barriss, then, since there's a pattern of behavior that had serious consequences well before the fatal shooting.