The pointed pick struck Trotsky’s skull, punching through his parietal bone and penetrating almost three inches into his brain. Trotsky let out [a] long, mournful cry [that Mercader never forgot]. Despite his injury, he fought back. He spat in Mercader’s face and began struggling with him, biting his hand. The sixty‐year‐old Trotsky put up such a fight [that] he broke Mercader’s hand, and the commotion drew Trotsky’s bodyguards. Bursting into the room they latched onto Mercader and started to beat him savagely. Only Trotsky’s intervention saved him.

“No … don’t … kill … him.” Trotsky labored to speak. “We… need … answers.” The men did as he said and restrained the bruised and bleeding assassin.

(Source.)