23 - Unwise Child by Randall Garrett

When a super-robot named Snookums learns to create his own superbombs, it quickly becomes clear that Earth is no longer a safe haven for him. In response, Dr. Fitzhugh, his creator, along with Leda Crannon, a child psychologist serving as Snookums’ caretaker, devise Operation Brainchild—a daring plan to transport the robot to a distant planet. However, their journey takes a dark turn aboard the spaceship when the medical officer is found murdered, and Snookums suddenly finds himself the prime suspect… - Summary by Mark Nelson