Even after gunning down a TV news reporter and cameraman during a live interview, Vester Lee Flanagan II continued to rage. But after a volatile career that had seen him fired at least twice for clashing with co-workers who recall him as an off-kilter loner, this would be the former broadcaster's last, brutal sign-off.

"I've been a human powder keg for a while...just waiting to go BOOM!!!" Flanagan wrote in a rambling 23-page note faxed to ABC News soon after the shooting.

Hours after he shot his former co-workers and then posted video of the attack to his Facebook page, Flanagan crashed a vehicle and shot himself. He died at a hospital later Wednesday, authorities said.

In the note, Flanagan — who had appeared on air using the name Bryce Williams — said he'd been discriminated against both for being black and gay. He listed grievances dating to the 2007 mass shooting at Virginia Tech and the more recent massacre of worshippers at a historic black church in Charleston, South Carolina.

When Flanagan was fired from Roanoke, Virginia, station WDBJ in 2013, he had to be escorted from the building by police "because he was not going to leave willingly or under his own free will," the station's former news director, Dan Dennison, said in an interview with a Hawaii station, Hawaii News Now (KHNL/KGMB).

Flanagan, 41, had "a long series of complaints against co-workers nearly from the beginning of employment at the TV station," said Dennison, now an official with the Hawaii Department of Land and Natural Resources. "All of these allegations were deemed to be unfounded." Though the claims were along racial lines, he said, "we did a thorough investigation and could find no evidence that anyone had racially discriminated against this man."

The victims of Wednesday's shooting — reporter Alison Parker, 24, and cameraman Adam Ward, 27 — were white; Flanagan was black.

The conflict described by Dennison in many ways echoed another, in 2000, when Flanagan was fired from a Tallahassee, Florida, television station after threatening fellow employees, a former supervisor said.

Flanagan "was a good on-air performer, a pretty good reporter and then things started getting a little strange with him," Don Shafer, the former news director of Florida's WTWC-TV, said Wednesday. He spoke in an interview broadcast by Shafer's current employer, San Diego 6 The CW.

Shafer said managers at the Florida station fired Flanagan because of his "bizarre behavior."

"He threatened to punch people out and he was kind of running fairly roughshod over other people in the newsroom," said Shafer, who did not immediately return a call from The Associated Press for comment.

Kimberly Moore Wilmoth, who worked with Flanagan at the Florida station, recalled him as "off-kilter" and someone who "never really made himself part of the team."

Recalling one of a number of incidents, Wilmoth said co-workers meant to tease Flanagan for a story he did on a spelling bee that made it sound as if the winner would get a case of Girl Scouts, rather than cookies sold by the group.

"The next day, somebody had a Girl Scout emblem on their desk and we made some copies of it and taped them to his computer," she said. "If he had only laughed, we would have all been friends forever. But he didn't laugh ... he got mad. And that was when I realized he wasn't part of the collegiality that exists in a newsroom and he removed himself from it."

In 2000, Flanagan sued the Florida station over allegations of race discrimination, claiming that a producer called him a "monkey" in 1999 and that other black employees had been called the same by other workers. Flanagan also claimed that an unnamed white supervisor at the station said black people were lazy because they did not take advantage of scholarships to attend college. The parties later reached a settlement.

Flanagan grew up in Oakland, California, and graduated from San Francisco State University.

Virgil Barker, who grew up on the same tree-lined street in the Oakland hills, recalled his childhood friend Wednesday with fondness.

"I know you want to hear that he was a monster, but he was the complete opposite," Barker said. "He was very, very loving."

Barker said he had lost touch with Flanagan over the years but remained close to Flanagan's sister, who still lives in the family's home across the street.

No one answered the door Wednesday morning at the white stucco house, with fruit trees in the front yard overlooking San Francisco Bay.

Before and after his work in Florida, Flanagan worked at a series of stations around the country.

They included a stint in 1996 at KPIX, a San Francisco station, where a spokeswoman confirmed he worked as a freelance production assistant. From 1997 to 1999, he worked as a general assignment reporter at WTOC-TV in Savannah, Georgia. From 2002 to 2004, he worked as a reporter and anchor at WNCT-TV in Greenville, North Carolina, general manager and vice president John Lewis said.

A former co-worker at the California station, Barbara Rodgers, recalled him only vaguely as "a young, eager kid out of journalism school," who "just wanted to be on TV and to do a good job."

Working in Georgia years ago, Flanagan was "tall, good looking and seemed to be really nice, personable and funny," said a former fellow reporter, Angela Williams-Gebhardt, who now lives in Ohio. The station's former news director, Michael Sullivan, said Flanagan was relatively inexperienced, but did a decent job, without any apparent problems.

But at Roanoke's WDBJ, Flanagan "got in lots of arguments with people," said LaRell Reynolds, a former production worker at the station. "I don't think anyone liked the guy."

After managers fired Flanagan, he worked as a call center representative for UnitedHealthcare in Roanoke from late 2013 to November 2014, the company said.

But in the days before the shootings, Flanagan assembled photos of himself on Twitter and Facebook, as if preparing to introduce himself to a wider audience. The postings continued after the shooting, when he tweeted that Parker had "made racist comments" and Ward had complained to human resources about him. Then, Flanagan posted video of the shooting online, showing him repeatedly firing at a screaming Parker as she tried to flee.

As word of the killings spread, friends from Oakland who knew Flanagan as a sociable kid who mixed easily in a high school with few racial tensions, struggled to connect those memories with the shooter shown on video.

"I don't remember anything bad about him," said Sasha Dansky, a high school classmate, recalling Flanagan's frequent appearance at parties. "He was just a nice, affable guy."

___

Geller wrote from New York. Associated Press writers Gary Fineout in Tallahassee, Florida; Garance Burke in Oakland, California; Holbrook Mohr in Jackson, Mississippi; Russ Bynum in Savannah, Georgia; Kristin Bender in San Francisco and John Raby in Roanoke, Virginia, contributed to this story.