The Boston Massacre happened when British soldiers in the Massachusetts Bay Colony in Boston opened fire on a group of American colonists. This resulted in the death of 5 of the American colonists. The soldiers were there to stop demonstrations against the Townshend Acts and keep order, but they failed and instead, ended up making people mad.
Technically, I don't think the soldiers are guilty of murder. This is because the definition of murder is: '<span>the unlawful premeditated killing of one human being by another.' War is lawful so... no I don't think they are guilty of murder. I am not 100% sure about whether or not they are guilty though.</span>