And we begin tonight with that horrific attack in downtown Toronto. A driver appearing to aim for pedestrians. That van coming to a halt on a sidewalk, but not until after so many had been struck and killed. A trail of the injured along the street, too, more than a dozen hurt. Then, the confrontation between the driver and police. Tonight, that suspect is in custody, his eye tentdy just released. Tom llamas leads us off from Toronto tonight. Reporter: Tonight, the race to save lives after the deadly van attack. Nine dead and more than a dozen wounded after a driver in this white van jumped the curb, plowing through pedestrians on a major street in Toronto. Vehicle, personal injury, intersection of Yonge street and finch avenue. Reporter: It was lunchtime, just before 1:30 P.M. The van driving 16 blocks, nearly a mile and a half, ramming into people again and again. He just went on the sidewalk, he just started hitting everybody, man. He hit everybody on the sidewalk. Anybody in his way, he would hit. The bus stop, everything all shattered. There was a lady in there I saw. I just stopped and I looked and I went after him and all I see is just crumbling up one by one. Reporter: Eyewitnesses describing a scene of pure panic. Everyone started running and screaming and he hit this one lady and she went flying. And he hit another lady. I didn't see. I was running at that point and you could hear them at like dropping. Reporter: Police finally cornering the van. Investigators are now scouring the video of the standoff that came next. The driver pulling an object from his pocket, pointing it at an officer, staring him down with this warning. I have a gun in my pocket. I don't care. Get down. I have a gun in my pocket. Get down. Get down or you'll be shot. Shoot me in the head. Reporter: That didn't happen. The officer took him down, handcuffing him on the pavement. Officers taking him into custody. With this unfolding, swarms of first responders racing to the scene, finding multiple victims already being triaged by good samaritans. There was four bodies on the ground. Police and ambulance hadn't arrived yet. People were trying to revive them. Reporter: A grim scene. Victims lying all over the street. Bodies covered with Orange tarps. Shoes left abandoned in the middle of the street. The injured, loaded onto stretchers and raced to nearby hospitals. This is going to be a long investigation, with multiple witnesses. We have a lot of cameras. Reporter: Tonight, police still searching for a motive behind the mayhem. So, let's get right to Tom llamas, live from Toronto. And authorities believe this was deliberate, they're calling it an attack? Reporter: That's right, Canadian officials are calling this a horrific attack, David. And we've just confirmed the name of the suspect allegedly behind the wheel, 25-year-old Alec manassian. There were so many victims in this case because, David, it happened in a very busy area of Toronto. But in front of so many eyewitnesses and surveillance cameras, now all part of the investigation. David? Pouring through the video at this hour. Tom llamas leading us off tonight. Tom, thank you. There is also heightened alert at home tonight. The NYPD saying they've deployed counterterror officers late today. ABC's chief jous tis correspondent Pierre Thomas live with us tonight from Washington. What have you learned from your sources about the suspect? Reporter: David, he's believed to be from the Toronto area, and they believe this was an intentional act. They are sorting out if this is terrorism or not, but these kind of vehicle attacks have become the preferred method of terrorists around the world. More than 100 people have been killed and 500 injured in these kind of attacks since 2016. That's why, David, you're seeing cities put up more and more barriers to try to protect pedestrians. Just a horrific scene. Pierre, thank you. Meantime, tonight, an arrest an takedown after that killing