And we turn next to Ferguson, Missouri, where Michael brown was gunned down in broad daylight and no one knows what the policeman says about why. Tonight, we're hearing from someone close to that... See More
And we turn next to Ferguson, Missouri, where Michael brown was gunned down in broad daylight and no one knows what the policeman says about why. Tonight, we're hearing from someone close to that officer who is still in hiding as a city braces for new protests, new violence and another police shooting has taken place. ABC's Alex Perez is there. Reporter: With emotions already on edge, tonight, new unrest near Ferguson. Protesters gathering after officers in nearby St. Louis today shot and killed a 23-year-old african-american man. It's crazy, man. Reporter: St. Louis police say the man was a robbery suspect, screaming and waving a knife at the office I think we can all understand what's going on in Ferguson, but I think every police officer that's out here has a right to defend themselves and the community. Reporter: Today, the Missouri National Guard still on the streets of Ferguson, after a night that saw the most arrests, since unarmed teenager Michael brown was shot by police officer Darren Wilson. Protesters and police again going held ad to head. This stark image -- an intense flame after an officer fires tear gas into a crowd. A woman helping one man who wouldn't open his eyes after he was gassed. A small army in riot gear pushing protesters forward. Jail records now revealing 78 people were arrested last night, more than twice the number initially reported. Police blaming outsiders for stoking the unrest. Only four arrested were from Ferguson. Most from the St. Louis area. And 18 were from other states, including New York, California and Illinois. People here are waking up with tear gas in the air and on some nights looted stores and rubber bullets on the ground and it makes them upset and angry. Reporter: We're learning more about Darren Wilson. His good friend speaking out. I can tell he's struggling. I can tell this is really hard on him. Reporter: His friend, so concerned for his own safety, he asked us to conceal his face. Darren's a good person and people have just immediately jumped to label him as a cold-blooded murderer. Reporter: Wilson has already spoken to investigators and the grand jury will likely start hearing evidence tomorrow. Alex Perez, ABC news, Ferguson, Missouri.
This transcript has been automatically generated and may not be 100% accurate.