Bodies show signs of torture in liberated Ukrainian town

Izyum, Ukraine — In a wooded area in Izyum, Russia tried to hide its crimes. Investigators, led by Kharkiv's chief war crimes prosecutor, are determined to uncover them after the area was liberated from Russian control. 

The smell — death on an industrial scale — is overpowering. The work is overwhelming and exhausting for those on the scene. 

There are so many graves that CBS News stopped counting after 100. Investigators say they've found over 400 shallow graves, and at least one of those is a mass grave containing the remains of at least 17 Ukrainian fighters. But CBS News mostly saw the bodies of civilians.