Evana Roth said Friday that her husband, Raymond Roth, had sent her son Jonathan emails referring to a possible plot.
She provided copies at a news conference with her attorney. One instructs Jonathan to call his father Sunday in Florida to update him on developments in New York.
Jonathan Roth reported his father missing Saturday at Jones Beach. That set off an extensive search. On Thursday, Roth got a speeding ticket in South Carolina.
Police say Roth has said he plans to return to New York, but he hasn't surfaced. His son's whereabouts also are unknown.
