The body of Cecil Lockheart was found at the bottom of a cliff. He was clothes in hiking boots, mitts, several jackets, and woolen trousers. The suspect recalled, "I retunred to comp early to make dinner when I saw Cecil and his wife arguing. They've been married for several years and often had heated discussions, so I didn't want to intrude and hid behind a tree. Suddenly, Cecil picked up a rock and delivered a fatal blow to her head. Just then, he saw me, and was so startled he turned and ran. Apparently, he forgot about the cliff and feel to his death.
When the lab checked the rock that killed the wife, it found Cecil's fingerprints on one side and his wife's blood on the other.
The suspect was immediately arrested.
Why?