A Cannon Ball man has been found guilty of slashing his brother-in-law's face with a knife, on the Standing Rock reservation.

Burdon Fabron Lester, 24, was found guilty on Wednesday of assault resulting in serious bodily injury and assault with a dangerous weapon, U.S. Attorney Drew Wrigley said.

A sentencing date has not been set. Lester faces up to 20 years in prison and a $500,000 fine.

Lester is accused of cutting Chandler Dwarf's face with a knife on March 23. Authorities said the 4 1/2-inch laceration extended from Dwarf's cheekbone to his chin, resulting in a permanent scar.

Assistant U.S. Attorney Rick Volk said Lester and Dwarf were drinking alcohol together before the attack.

Dwarf, 27, pleaded guilty earlier this month to hitting his wife in the face with a baseball bat. Patricia Dwarf, who is Lester's sister, suffered a broken jaw and other injuries in the September 2006 assault.

Chandler Dwarf faces up to 10 years in prison and a $250,000 fine for assault resulting in serious bodily injury.

His sentencing is set for Oct. 29.

Volk said the baseball bat attack "was at least part of the argument" between Lester and Dwarf in March.

Lester said during the two-day trial in Bismarck that he was acting in self-defense.