The Legionnaire Who Killed is a Legion of Super-Heroes story published in Adventure Comics #342 (March, 1966), by Edmond Hamilton and Curt Swan.
The Legionnaires are having fun times, playing board games and dancing, but Thom Kallor, “Star Boy”, cannot join them. Star Boy has been depressed since Nura Nal, “Dream Girl”, who he fallen for, resigned the team. After testing several applicants for the team, Thom sets off for primitive planet Karak to meet his parents, who are doing astronomical research, and see that they get off safely.
On Karak, Star Boy finds an explorer called Jan Barth living in his parents' observatory. Jan is explaining Star Boy that their parents have already left for Xanthu, when an unknown ship lands. A man walks out of the ship, aiming a gun at the duo, and shoots Jan when he tries to pull his own weapon out. Star Boy tries to crush the murderer -who has identified himself as Kenz Nuhor- under his own gravity, but the Nuhor's special shield deflects Star Boy's power back at him, causing him to fall to the ground. Nuhor takes a minute to explain he was in love with Dream Girl, but she wouldn't marry with him because she loves Star Boy, so he vowed to her face find and kill Thom.
Suddenly, Nuhor is distracted by the arrival of a space-flier. Nuhor recognizes Dream Girl's space-flier and assumes she has come to save Star Boy, but she is too late to stop him. However, Star boy takes advantage of his distraction to crawl forward, pick Jan's gun which dropped right in front of him, and shoots Nuhor. Dream Girl has seen everything, though, so that when Star Boy is able to move again, she takes him back to Earth and to the Science Police Headquarters. Dream Girl testifies in Star Boy's behalf, and he is cleared of all charges.
When Star Boy returns to the Legion Clubhouse, though, he finds an unpleasant surprise: since he has taken one life, breaking the Legion code, current leader Brainiac 5 demands he is taken to the detention room and trialed. Brainiac appoints himself as prosecutor and Saturn Girl as judge, and Superboy volunteers to act as Star Boy's lawyer, since he will not blame Star Boy for acting in self-defense.
Tropes:
- Artistic License – Law: The circumstances of Star Boy's trial would never fly in a real life serious courtroom, society future or not. After demanding a trial and appointing himself - a concerned party - as prosecutor, Brainiac 5 appoints Saturn Girl as judge and juror, prompting Superboy - another concerned party himself - to appoint himself as Star Boy's lawyer. Needless to say, neither of them have any legal training, and rather than reviewing facts and evidence during the trial, both Brainiac and Superboy resort to inane "What about you?" arguments.
- Attack Reflector: Kenz Nuhor owned a special shield which reflected Star Boy's gravity-increasing attack back at him.
- Batman Grabs a Gun: Thinking he had no other options at the time, Star Boy grabs a guy's sidearm to kill Kenz Nuhor, who was shielded from his powers. Brainiac 5 deems he could have dropped one tree branch Nuhor's head, and berates Star Boy for not thinking flexibly enough during this life-threatening situation.
- Bittersweet Ending: Star Boy is expelled from the Legion, but he joins the Legion of Substitute Heroes together with Dream Girl.
- Childhood Friend Romance: Kenz Nuhor was in love with Nura since they were kids. When she turned his proposal of marriage because she loved someone else, though, Nuhor decided to kill Star Boy.
- Continuity Nod: Nura Nal joined and quit the Legion in Adventure Comics #317.
- Courtroom Antics: The trial for Star Boy includes the jury watching videos completely unrelated to the case, Superboy having team's pet Proty turn into an alien beast to barge into the courtroom and try to scare Brainiac, and the female jurors voting not guilty primarily because they find Star Boy's romance with Dream Girl cute.
- Courtroom Episode: The episode is focused on Star Boy's trial after he killed an outlaw in self defense, violating the Legion's code against killing.
- Covers Always Lie: The cover features Star Boy arguing that he killed in self-defense, and Saturn Girl, Dream Girl and Superboy berating him over breaking the Legion code and expelling him. In the proper story, Nura testifies in behalf of Star Boy, Kal argues that killing in self-defense should be allowed, and Imra doesn't speak her opinion one or another way until the voting begins. Furthermore, Superboy was his defense counsel.
- Crime of Self-Defense: Kenz Nuhor, a jilted lover of Dream Girl, attacks Star Boy out of jealousy, using a special shield to turn his gravity powers back onto him. Knowing he was doomed if he didn't defend himself, Thom picks up the blaster of a fallen bystander and shoots down Nuhor. Although he was legally cleared of any crime, a Legion court-martial deems that he could have solved the problem non-fatally (by aiming his power above the shield, dropping an overhead tree branch onto Nuhor and pinning him down with it), and as killing is against the Legion Code, he iss expelled. He then joins the Substitute Heroes together with Dream Girl before ultimately being allowed back into the Legion proper.
- Hoist by His Own Petard: After being rejected by Dream Girl, Kenz Nuhor vows to her face to kill Star Boy. When he is about to kill Star Boy, though, Nuhor notices Nura has tracked him down and becomes distracted by one second, giving Star Boy the opportunity to kill him. Likewise, Nura being present allows her to testify in Star Boy's behalf, clearing him of charges.
- Imagine Spot: At one point, Star Boy daydreams about Dream Girl standing in front of him.
- Imposter Forgot One Detail: Legion's pet Proty shape-shifts into a Scorpion Beast to trick Brainiac, but Querl smugly points out that the monster's claws are not dripping acid, so the Scorpion must be an illusion or a shape-shifter.
- Murder the Hypotenuse: Kenz Nuhor vows to murder Star Boy after being rejected by Dream Girl.
- Not Good with Rejection: Kenz Nuhor has always loved Dream Girl, but Nura turns his marriage proposal down because she is in love with Star Boy, prompting Nuhor to vow to her face to find and kill Star Boy.
- Poor Communication Kills: The whole ordeal might possibly have been averted if Nura had warned the Legion that a lunatic was tracking Star Boy down to murder him.
- Shipper on Deck: Superboy guesses that the reason that most of female Legionnaires vote not guilty is that they like Star Boy and Dream Girl's couple.
- Spanner in the Works: Kenz Nuhor finds Star Boy talking to explorer Jan Barth, and murders the latter to prevent him from interfering with his revenge. However, Star Boy is able to kill Nuhor thanks to Jan's gun, which dropped right in front of him.
- Superdickery: The cover has Saturn Girl, Dream Girl and Superboy berating Star Boy over breaking the Legion code, dismissing the fact that he killed in self-defense and expelling him. In the proper story, Nura and Kal advocate for Star Boy's right to self-defense, and Saturn Girl doesn't give her opinion on the matter until voting begins.
- Terrible Interviewees Montage: The story begins with the Legion interviewing new applicants. Calamity King is turned down due to the random nature of his disaster-causing power, but Color Kid is suggested to try the Legion of Substitute Heroes.
- Thou Shalt Not Kill: Star Boy is expulsed from the Legion for killing in self-defense, in spite of Superboy and his Flying Brick teammates -Supergirl, Mon-El and Ultra Boy — voting to not expel him. The reason? Because it's easy for him, Superman, to have a code against killing when there aren't a lot of things that can hurt him, but other people may have different circumstances than him and he will not expect them to stick to his code.