Katniss and President Coin didn't get along during their time in District 1, with Coin not believing that Katniss had what it took to lead a rebellion. Coin appeared to be a fervent supporter of the Rebellion, but she took advantage of the movement to further her own political interests.
Snow laughs after Katniss killed Coin because he enjoys the irony of the situation. He avoided the official execution ceremony, even though Panem's citizens still take their revenge on him, while Katniss ends up snatching away the victory and power that Coin thinks she has successfully secured.
It is still possible that she genuinely wants to make Panem a better place, but her methods become inhumane. Coin feels threatened by Katniss' rebellious nature. In the end, her own delusional idea of Panem is her undoing, since she ignorantly trusts that Katniss is okay with her being the new president of Panem.
Boggs reveals that Coin had wanted to save Peeta from the arena instead of Katniss. Katniss represents a threat to Coin, and Katniss made the situation worse by forcing Coin to rescue the other victors. Boggs reminds Katniss that she has outlived her usefulness to Coin.
The Life of President Alma Coin: The Real Villain of the Story (Hunger Games Explained)
Do people understand why Katniss killed Coin?
In The Hunger Games series, Katniss killing President Coin instead of President Snow surprised many. Still, it was because Coin was revealed to be a ruthless leader with her own political interests.
Katniss searches his eyes for signs of emotion but only finds amusement in them. She remembers that they did indeed promise not to lie to each other anymore, and she realizes that Snow wasn't lying to her about Coin's role in the parachute bombing.
Katniss speculates that Coin deliberately sent Prim to die in the Capitol bombing in order to fully gain her trust, but it's never outright confirmed or denied.
Deceased. Primrose Everdeen - Blown up by President Coin's parachute bombs. Messalla - Melted in an unknown pod that trapped him before burning the flesh off him.
Peeta, Annie, and Beetee vote no, while Johanna and Enobaria vote yes. After some thought, Katniss demands to kill Snow. Once she receives an agreement, she votes yes, for Prim. Realizing something is up (as Katniss would never do that), Haymitch votes yes, too.
In The Hunger Games series, Katniss killing President Coin instead of President Snow surprised many. Still, it was because Coin was revealed to be a ruthless leader with her own political interests.
Haymitch Abernathy, the mentor for Katniss and Peeta in The Hunger Games, won his own Hunger Games through smart tactics and outsmarting his opponents. Winning the Hunger Games came at a great cost for Haymitch, as President Snow ordered the death of his family and girlfriend as punishment for his rebellion.
Before the Capitol battle, Gale had explained to Katniss his series of bombs designed to feed off human compassion: a small bomb would go off, and then when medical aid rushed in, a second bomb would go off, killing those people as well. Incidentally, it's this exact type of bomb that took Prim's life.
Did Gale mean to kill Prim? No, Gale did not mean to kill prim but he still designed the bomb. But, although he holds a small fraction of responsibility, he never meant for Prim to get hurt.
Coin wants to remain in power after the revolution, and if Katniss isn't going to support Coin's leadership, then Coin will use her in whatever way she can to give the rebellion momentum. For now, that might mean turning Katniss into a martyr. For everyone's safety, the crew sets up an around-the-clock guard on Peeta.
Prim tried to stop Katniss since she knew she would most likely not survive the horror of the Games; but Gale Hawthorne held her back. Katniss' bravery was strong in this part. Gale taking Prim away at the reaping.
Why did Peeta stop Katniss from eating the Nightlock?
3) He stops her taking the nightlock pill after she kills Coin. He knew her well enough to know that not only would she try to kill Coin but that she would then try to kill herself straight after with the nightlock pill.
In the book, Katniss thinks that Snow wants the children close to the mansion to “form his human shield”—he assumes that the rebels won't bomb his home if it means killing innocent children.
Snow can't stand to see a young woman betray a young man's affection—his view of what happened 65 years ago. And so he takes out his old, festering wound on Katniss.
According to the star behind Effie, Elizabeth Banks, she and Haymitch's Woody Harrelson improvised the scene. Considering she's been adamant about the characters having some romantic connection, it only makes sense that they'd share a goodbye kiss. It's very on-brand for Effie, as well.
It became clear then that Coin had the same mentality as Snow. To her, children were a tool to be used against those that loved them. They were chess pieces to be maneuvered and sacrificed. If Coin were willing to kill Capitol children in the Hunger Games, she would undoubtedly be willing to in a war.
After reading the book and watching the film, it seems clear that Lucy Gray realizes Snow was responsible for the death of his friend Sejanus Plinth (Josh Andrés Rivera). If Snow could sell his best friend down the river for personal gain, it was only a matter of time until he did the same with her.
Control: As the leader of Panem, President Snow wanted to maintain his power and control over the districts. Katniss became a symbol of rebellion and hope for many people, which threatened Snow's authority.
Gale and Katniss did not see each alone until a few weeks after the end of the Hunger Games, at their meeting place in the woods. They shared an emotional reunion. At the end of a day of hunting, Gale spontaneously kissed Katniss and told her that he “had to do that, at least once.”
