Why was Cinna killed in the second book of the Hunger Games?

Instead of killing him right away, President Snow waits until the very last second as Katniss gets into the tube to take her to the arena. As she begins to ascend, she watches in horror as Cinna is beaten to death by Peacekeepers

This is what you are asking i think... hope this helped sky

Cinna was killed for showing approval of the Revolution towards the capital in his works of art in Katniss's clothes.

Explanation:

            He was hurt in front of Katniss when she was going up the tubes that leads to the arena. He was later took to another room when there he was tortured until he told the capitol government the plans about the revolution , which he did not tell them about anything. The guards finally asked him, "Tell us about the plans for the revolution o you die", to which he later responded, "Never'. Then the guard shot him in the temple of his head and he died immeadiantly.

second person

explanation:

note the heavy uses of "you", "your", as well as "he".

~