T.J. Robert Hunt pleaded no contest to arson, according to online court records. Three other counts were dismissed.
Sentencing is scheduled for July 14 in Door County Circuit Court.
Hunt and Justin Baker set fire to the residence of Jason Johnson. Johnson was convicted in Michigan in 2009 of 2nd Degree Criminal Sexual Assault, according to the state registry. Authorities said the two cited Johnson's sex offender status as the reason for the fire.
Baker returns to court April 29 for a plea hearing.