Human Rights Watch says those details can be used to show who fired the rockets that carried the Sarin gas. The rights group says two of the rockets hit the Zamalka and Moadamiya areas of Damascus. The UN documented the angles at which the rockets landed. Based on that information, Human Rights Watch says their flight path can be calculated. And that data suggests they were fired from the base of the Syrian Republican Guard 104th Brigade, less than 10 kilometers away.