Distrustful of the apes, Dreyfus arms his community using the Fort Point armory. Maintaining his distrust of humans, Koba discovers the armory and later confronts Caesar, accusing him of loving humans more than apes. In response, Caesar severely beats Koba, but refrains from killing him. Koba returns to the armory, where he takes an assault rifle and kills two guards. Returning home, he secretly kills Carver. The generator is repaired, restoring power to the city. During the celebration, Koba sets fire to the apes' home, then, unseen to anyone else, shoots Caesar, who falls from the settlement's main tree. In the subsequent panic, Koba takes charge, implicating Carver in the shooting and convincing the apes to attack the humans. He leads them into San Francisco, where they plunder the armory and charge the tower, with many casualties. The apes breach the building and imprison the humans as Dreyfus flees underground. When Ash refuses Koba's orders to kill unarmed humans, citing Caesar's teachings, Koba kills Ash and imprisons any ape still loyal to Caesar.

Who shot caesar in dawn of the planet of the apes? Let's have some stream of consciousness first.
The relevant information to answer the above question is: During the celebration, Koba sets fire to the apes' home, then, unseen to anyone else, shoots Caesar, who falls from the settlement's main tree. So, the answer is Koba.