There was no mention of prior contact so once the assailant touches your daughter, it is an immediate threat that could result in bodily injury or death; there is no where to retreat so it is a justifiable shooting in Colorado but it will cost you time and money regardless. However, If this situation started by these guys yelling something from a distance, and then you confronted them resulting in the confrontation you described, you could be in trouble. In Colorado, your actions leading up to shots fired could be taken into consideration. If you have an opportunity to retreat, and don't take it; you could be in trouble. You better have your ducks in a row as to why you were in a situation necessitating the need for deadly force, or you could be facing charges; from what I understand, Colorado can be a legal shit storm if you use deadly force (like anything depends on jurisdiction).