streets overnight squaring off against police and the national guard. in the wake of another police shooting. abc's marci gonzalez is there. >> don't shoot! >> hands up! don't shoot! hands up! >> reporter: more protests miles away from ferguson after officers in st. louis shot and killed a man they say was coming at them with a knife. adding to the outrage still boiling over. another demonstration at the county prosecutor's office. following violent clashes between protestors and police. >> there is a dangerous dynamic in the night. it allows a small number of violent agitators to hide in the crowd and then attempt to create chaos. >> reporter: of the 78 people arrested, police say only 4 were from here in ferguson. they claim more than a dozen others came from out of state to join the protests that start every day as peaceful demonstrations, calling for action after the shooting death of an unarmed teenager more than a week ago.