Paramount+'s crime thriller, Mayor of Kingstown Season 4, has dropped its gripping penultimate episode. Among the other unsettling scenes from this episode of Mayor of Kingstown Season 4, Breen's prison massacre tops the list. It's quick, it's brutal, and it's intense.Unable to bear the humiliation from the prisoners, Will Breen lost his mind and went on a full killing spree. He started to kill the helpless prisoners with his shotgun, even when they begged for their lives. It was Cindy Stephens who put an end to the massacre. Just when Breen was about to shoot Kyle, the last prisoner in the cell, Cindy shot him dead. For Laura Benanti, the actor behind Cindy, this scene was not easy to shoot. In a candid chat with Entertainment Weekly, she revealed,"I found myself actually thinking about my children. A mass shooting anywhere is absolutely terrifying."Benanti added that for Cindy to pull the trigger and kill a fellow CO wasn't an easy task. It's not something that Cindy is exposed to every day. It's a tense situation, and Cindy does what she thinks is best. This will surely affect her conscience and might change her as a person, too, in the future seasons. But Cindy's actions will have consequences in the future. However, that remains a mystery as of now. Here's what Benanti said about it,"I cannot imagine what she saw and then having to do, even though it was the right thing to do. There's no way that doesn't change a person."Mayor of Kingstown Season 4 Episode 9: Why did Cindy kill Breen? View this post on Instagram Instagram PostCindy Stephens (Laura Benanti), the correctional officer of the Kingstown prison, decides to put an end to her fellow officer Will Breen's killing spree in the season finale. We know Breen wasn't in his right mind after a deadly altercation with an inmate; he was moved from the women's prison as per Warden Hobbs's orders. Turns out Hobbs was aware of his violent past. Anyways, when Breen was asked to clean out a cell in Ad Sec where an inmate (Terry) defecated all over, he felt humiliated.The prisoners laughed at him and insulted him as they chanted, "Breen eats sh*t." Unable to take in the humiliation, he brought a shotgun and started to shoot like a madman. He shot multiple prisoners, and just as he was about to shoot Kyle, Cindy Stephens appeared. Without giving any second thoughts, she pulled the trigger, killing Breen on the spot.Will Breen was no saint; the mocking and bullying got on his nerves. He tried to remain calm at first while cleaning an inmate's waste. However, when the prisoners started laughing and teasing him, he lost his calm. Keeping this in mind, it's also important for COs to handle such situations differently, and this is what brings us to a pivotal point, and that is regular monitoring of the mental health of prison guards, COs, and wardens. The prisoners are bound to mock them and even do things that would raise their tempers. But it is up to the prison officials to handle such tense situations smartly.Mayor of Kingstown is available to stream on Paramount+.Read more: Mayor of Kingstown Season 4 Episode 9 recapFollow SoapCentral for more such updates on Mayor of Kingstown Season 4.