(CNN) – Investigators found food wrappers, the imprint of a shoe or a boot, and an indent where someone may have slept.
It’s not clear whether they are traces of Richard Matt and David Sweat, two convicted murderers who escaped from prison almost a week ago.
However, tracking dogs picked up a scent, and authorities started focusing much of their search on an area just a few miles from the Clinton Correctional Facility.
District Attorney of Clinton County Andrew Wylie said, “If this is an actual true lead that the dogs are following on, we hope to be successful in the next 24 hours.”
The dogs picked up the scent at a gas station about a mile from the prison. Authorities are reviewing what limited security video there is from the store.
U.S. marshals caution the terrain in the area is difficult and the foliage is thick, making it relatively easy for someone to slip through.
U.S. Marshals Commander Robert Fernandez said, “They could have been in that area, they may, I hope; they are still in that area and that noose closes in on them, but they very easily could have slipped away, so we have to stay vigilant across the country.”
Commander Fernandez says the problem with thermal imaging is that it also picks up on animals like bears and deer, making it difficult to find men on foot.