A man who identified himself as "Stevie Steve" in a video he broadcast of himself on Facebook. Stevie Steve/Social Media/REUTERS

Steve Stephens, the 37-year-old Cleveland man who has been dubbed the "Facebook killer," was found dead in Erie, Pennsylvania, on Tuesday. He killed himself after being pursued by police, according to news reports and law enforcement.

Pennsylvania state police said Stephens was spotted Tuesday morning by officers and shot and killed himself after a "brief pursuit."

Stephens was the subject of a nationwide manhunt throughout Monday and into Tuesday and was wanted on a charge of aggravated murder. Police said he shot and killed 74-year-old Robert Godwin on Sunday when Godwin stepped out after an Easter meal with his family.

News of the shooting went viral on Sunday after Stephens posted a video of it on Facebook.

During a press conference on Tuesday afternoon, Cleveland Police Chief Calvin Williams told reporters that Pennsylvania police had received a tip from someone who said they saw a white Ford Fusion, the car police had said Stephens was driving, in a McDonald's parking lot.

As officers approached the area, Stephens took off in his car. When officers went to the car after a short pursuit, Stephens killed himself, Williams said.

"Thank you to the brave @PAStatePolice troopers for their vigilance in pursuing the Facebook killer," Pennsylvania Gov. Tom Wolf tweeted. "Thankful no one in PA was hurt."

Authorities alerted people across the nation on Monday that Stephens was thought to be "armed and dangerous." Schools in Philadelphia were put on lockdown Monday afternoon while police investigated reported sightings of Stephens in the area, though they said there was no evidence he had been there.

In the horrific Facebook video, which authorities confirmed was legitimate, Stephens was driving and could be heard saying, "Found me somebody I'm going to kill, this guy right here, this old dude."

Stephens exited the car and approached Godwin. He asked Godwin how old he was before pulling out a gun and pointing it at Godwin's head. Godwin could be seen attempting to shield himself before Stephens fired the gun. Stephens walked back to his car and drove off.

Stephens and Godwin did not appear to know each other, according to authorities.

"From what we can tell now, it's just a random person that he picked out," Williams said on Monday. "We don't know why."

Stephens' mother told CNN that when she last saw him, on Saturday, he told her that it would be "a miracle" if she ever saw him again. When the two spoke the next day, he told her he was killing people because he was angry at his girlfriend, she said.

In another video Stephens posted on Sunday, he claimed to have murdered 13 people and said he was going to kill more. Speaking into a phone, he said he "snapped" and was "about to keep killing until ... until they catch me, f--- it." He could also be heard encouraging the person on the other end to watch the video of the shooting he had uploaded to Facebook.

Facebook on Sunday took down the video of the shooting. It has disputed reports that it took three hours for it to be removed.