Yes, his insurance probably *can* deny your claim. Most auto liability policies contain an exclusion that absolves the insurer of its obligations in the event of deliberate wrongful behavior, like crimianl assault; the insurance is meant is to protect an innocent person who has an accident, not to allow a criminal or wrongdoes to escape some of the economic consequences of his or her actions. If the attacker's policy contained such an exclusion, the insurer would not have to pay. Note that this does NOT mean that you can't sue the attacker--whether or not he has insurance, you can sue him for your injuries, damages, losses, etc. from the assault. If he has income or assets (including vehicles or real estate/property), you should be able to collect, even if he has no insurance.