David Chislton, 42, was sentenced to 47 years in prison on nearly two dozen charges.
Chislton pleaded guilty to holding his girlfriend hostage at gunpoint, then setting his apartment complex on fire in 2017. The fire displaced dozens of families.
After he was sentenced, Chislton appears to sucker-punch his attorney Aaron Brockler.
Deputies said they will complete the paperwork to file additional charges against Chislton related to the attack.