LITTLE ROCK (KATV) — It’s been one week since former police chief, Grant Hardin, escaped from the North Central unit in Calico Rock—where he was serving time for two violent crimes: the 1997 rape of a Rogers teacher and the 2017 murder of a Gateway city employee.

The 56-year-old slipped away from the prison just before 3 p.m. on May 25, dressed in a fake law enforcement uniform.

The Arkansas Department of Corrections says they’re still chasing down leads, but tips from Faulkner and Sebastian counties in Arkansas—and even Howell County, Missouri—haven’t panned out.

The focus remains on North Central Arkansas, a rugged region filled with thick forest, caves, and rivers.

"We understand that there is that thought of if he's going to take this much planning to get out he probably has a plan to get out [of state] as well. The search is still being primarily focused in the North Central Arkansas region. Mainly for the fact our mode of operations when this happens is until we get verifiable evidence or a verifiable tip that that he is not in the area, we have to assume that he is in the area and keep that as the search," Rand Champion, a spokesman for the Arkansas Department of Corrections, said.

Crews are using every tool available—drones, dogs, helicopters, even horseback patrols—to search the area.

"Obviously if we get something that's credible that re-shifts our focus, then we'll re-shift our focus," Champion said. "Just considering all the different challenges that the Calico Rock area and the different places that are available for a hiding place and available for somebody to lay low for a few days, a few weeks. That's why that remains a key area of where we're searching."

The reward for information leading to Hardin’s capture is now up to $25,000, offered by the U.S. Marshals and the FBI.

Hardin is now facing an additional charge of second-degree escape in Izard County.