The massive manhunt for two murderers who made a daring escape from an upstate New York prison continued today. 

Fox News reported that federal agents, corrections officers and Essex County Sheriff's Office deputies spent most of the day searching around Willsboro, a town of about 2,000 people, for convicted killers Richard Matt and David Sweat. The men escaped from the Clinton Correctional Facility sometime before Saturday morning. 

Matt's half-brother, Wayne Schimpf, told Greta Van Susteren tonight that Matt would kill again if he had the opportunity to do so. 

"He threatened to kill me and he's killed others before," Schimpf said. "I would not put it past him. He's a very dangerous man."

Schimpf said that Matt "is the only man he's ever been afraid of." 

He also shared that Matt has escaped from other prisons in the past and that his "worst nightmare" has come true with him escaping again.

"If anybody gets this to him, or somehow he does see this, please turn yourself in," Schimpf pleaded. "And let everybody else be at rest, because a lot of us are scared for our lives. So please turn yourself in." 

Watch the video above.

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