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.)

Also when his bodyguards came in, he told them not to kill the assassin because they needed him to talk