Even on a fully justified shooting where the shooter is absolved of criminal charges, it is common for an ambulance chaser to run to the family of the person shot and pursue a civil suit for "violation of civil rights" or some similar crap. That means hiring a lawyer and working through the suit. It is very expensive. When you pull the trigger, expect 1 to 3 years of legal wrangling at a cost of $100,000. That's why you buy insurance. It's to cover in case of an unlikely event so you aren't personally financially wiped out.
Michael Brown's family (Ferguson) sued for loss of future income (from a common street thug) to support the parents. The parents got a pretty good payday from the cop's insurance. $1.5 million for "wrongful death". See lawsuit