PULLMAN, Wash. -- Police in Pullman, Wash., say they've arrested a 23-year-old male Washington State University student for investigation of assault in the beating of a Professor Dr. David Warner.
The arrest of a 21-year-old woman was announced earlier Wednesday and police say they're looking for two more male suspects.
Police Chief Gary Jenkins said Joshua Nantz came to the police station Wednesday night at detectives' request and was arrested.
Police say the woman - also a WSU student and Pullman resident - is accused of rendering criminal assistance and providing false statements.
An anonymous tip received over this past weekend led to the arrest according to police.
David Warner remains in critical condition at a Spokane hospital. Police say he was beaten about 2 a.m. on March 30 while intervening in a fight between an acquaintance and a group of college-age people.
The Associated Press contributed to this report.