Jeffrey Marks, the general manager of WDBJ, spoke to Stuart Varney on "Your World" to discuss the murder of a WDBJ reporter and cameraman during a live broadcast.

Marks said that he not only knew the shooter, Vester Lee Flanagan, he disciplined him when he previously worked for the station.

Marks said that Flanagan was an unhappy man who had difficulty working with people and controlling his anger.

"He had a short fuse," Marks said.

Marks explained that Flanagan's work was not up to the standards they hoped for, so he tried to give Flanagan coaching, which he did not take. Eventually, the station decided to part ways with Flanagan.

When he was dismissed in 2013, Flanagan did not take the news well and police officers were called in to escort him from the premises, Marks said.

Marks added that he was unaware that Flanagan had worked for several newsrooms before he joined WDBJ, as Flanagan applied under a different name.

Watch the "Your World" interview above.

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