ROANOKE, Va. — Vester Lee Flanagan II’s unstable behavior terrified his colleagues — including a female reporter who called the station from an assignment because she thought he was about to beat her up.

“She called into the station really afraid, saying that she felt he was going to hit her. He was getting in her face,” WDBJ TV reporter Melissa Gaona told The Post Thursday.

“She was legitimately afraid that he was going to fight her like a man would with another man.”

Referring to Flanagan by the name he adopted, Gaona said she experienced “a side of Bryce that scared me” on Feb. 1, 2013, the day he was fired.

“He was angry and hyper, and he looked paranoid, and he was pacing back and forth,” she said. “I pulled him aside to talk to him and try to calm him down. He said he felt like he was going to do something stupid.”

Another colleague, cameraman Trevor Fair, said Flanagan was notorious for his ­temper.

“It was scary. Slamming his hand on the dashboard. It was the Incredible Hulk or something,” Fair said.

Gaona said she “worked closely” with murdered colleagues Adam Ward and Alison Parker and was horrified by of their final moments.

“I can’t get the video out of my head,” she said, wiping away tears.

“The fact that they saw that terror before they took their last breaths is just devastating.

“I had no idea he could be capable of this.”