NY Prison Escape: Inmates Kept Notes About Escape Plan on Cell Walls, Source Says

Comes as investigators believe the trail has gone cold.

— -- The convicted murderers who remain at large kept notes on their cell walls and inside the pipes that they used as their escape route ahead of their break from an upstate New York prison 11 days ago, an official involved in the investigation told ABC News.

The notes had in turn served as a trail of clues for investigators, the source said, though authorities now face the prospect of a dearth of new evidence.

Three officials briefed on the ongoing search in upstate New York told ABC News that the consensus is that the trail has grown cold.

There are currently discussions among senior state and federal officials who are trying to decide what the next steps should be and what, if anything, should be said publicly, sources said.

"I don't know if she was plan A, plan B, or plan C," Clinton County Sheriff Dave Favro told ABC News of her alleged intended role as a getaway car driver.

The New York State Police announced today that the dragnet is expanding and shifting to other areas surrounding Dannemora based upon information gathered during the investigation.

Officers from multiple law enforcement agencies have searched over 16 square miles to date and have followed more than 1,200 leads, authorities said.