PEORIA, Ariz. - News spread quickly through Ronald Mollenhauer’s old neighborhood after the Arizona Department of Public Safety started knocking on doors.

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"Very sad having somebody that close to you that you know that you think that is never going to happen,” says Carla Emehiser who lived next door. Emehiser said Mollenhauer was going through a tough time recently.

"He had a daughter in Chicago that evidently had recently had a child he didn't know about and was very distraught because he had not found out from her,” she said.

Emehiser said she doesn’t know if this had anything to do with why he was at the airport, but says he usually tells her if he plans to leave town.

“I don't know if he went down there with thoughts he might take off and got very upset,” Emehiser says

Two neighbors who did not want to be identified said they believe Mollenhauer was not a drinker.

"Not any more. He had been. He admitted that,” said one of the neighbors.

Neighbors said they think Mollenhauer stopped drinking after being diagnosed with cancer.

They believe he was battling liver cancer, which forced him into a life of sobriety. The toxicology reports are not yet public, and so questions still swirl around just what happened.

One neighbor has a theory that doesn’t involve alcohol.

"I don't think he was drunk. I guarantee that. I think he just got confused."