We want to turn next to a scary situation on a greyhound bus. A 911 call coming from on board. A passenger allegedly with a gun threatening to kill others on board and triggering a police chase that ended across state lines. ABC's Marci Gonzalez has more. Reporter: Tonight, a suspect in custody accused of prompting a massive police pursuit. This is insane. Reporter: While threatening passengers on this greyhound bus. That he was gonna kill us, that he was gonna put a bullet in our head. Reporter: Some of the 37 people on board that bus, traveling from Milwaukee to Chicago around 10:00 Friday night, calling police. It did look like he had a weapon. Reporter: The bus not pulling over leading to a high-speed chase. The bus driver had no idea it was happening. Reporter: Officers from Wisconsin and Illinois shutting down the highway in both directions, throwing down stop sticks. Tires are starting to shred on the bottom. Reporter: The greyhound finally coming to a stop. They made us all get off one by one, with our hands up, had guns to us. Reporter: Police arresting 33-year-old marguerito vargas Rosas. They say the undocumented immigrant from Mexico is now charged with making terroristic threats and disorderly conduct. This is a situation that really could have gone in a different direction when we think abouts with's happening our country and mass shootings. We dodged a bullet. We really did. Reporter: Police say no one was hurt and they did not find a weapon. Cecilia. Okay, Marci, thank you.