In the Tate/LaBianca murders, there were five killers. Four girls and one man. There was no DNA testing then, so evidence of that sort was nonexistent. Plus police science was not as advanced as today. I imagine the police already know if there were more than one killer at the UofI in Moscow.
FWIW.
L.W.
"Always go straight forward, and if you meet the devil, cut him in two and go between the pieces." (William Sturgis, clipper ship captain, 1830s.)
