Authorities encountered Stein on the college campus in Hempstead, New York, and asked the third-party candidate, who has not garnered enough support to participate in the debates, to show the proper credentials, which she could not do, police said.
She was “nicely escorted” off the grounds around 2:30 p.m. Eastern time, a Nassau County Police Department spokesman told ABC News.
Stein tweeted about the incident, saying she was on the campus “doing an interview” when police put her and her team “in a van” and escorted them off the school’s grounds. Earlier, Stein’s campaign said she obtained a credential to go in and do interviews at the media filing center in the early afternoon.
Stein had planned to challenge her exclusion from tonight’s event by hosting a rally outside the secured perimeter of the debate hall beginning, around 5 p.m. Eastern time. She said she will be live on Twitter’s Periscope app answering the same questions as Democratic nominee Hillary Clinton and Republican nominee Donald Trump on the debate stage.
Stein’s campaign said she will not “risk arrest” this time, because there is an outstanding warrant for her arrest over her involvement in a recent protest against a controversial pipeline project in North Dakota. Still, her campaign spokeswoman Meleiza Figueroa said they will attempt to get the “spirited demonstration … as close to the gates as possible."
In 2012, Stein and her running mate were arrested outside Hofstra University when they tried entering the premises during a presidential debate between President Barack Obama and then–Republican nominee Mitt Romney.
ABC News’ MaryAlice Parks and Jordyn Phelps contributed to this report