OAK LAWN, Ill. (CBS) – It was 12 hours from stick-up to capture.

CBS 2’s Jim Williams on Monday went back to the scene of a weekend bank heist to survey the damage.

As officers returned to the bank, yards away was evidence of the long and painstaking search for the robber. A roof torn open, insulation everywhere.

“Oh, it was very tense, there’s no doubt about that. We knew that he was armed, and we knew he was in that building,” Oak Lawn Police Chief Bill Villanova says.

The building, the Ranch Manor Shopping Center, was surrounded by police right after an armed man robbed the Bank of America branch Saturday afternoon.

SWAT teams stood ready, and other officers evacuated people who worked at the mall, including Mike Callahan of the G and L Trophy and Gift store.

“I had no time to grab my cell phone. My co-worker had to leave her purse and her bag here,” he says.

Some officers dug through the roof, certain the suspect was right there. Police say they had a detection device and told the suspect they knew he was there. But the suspect said nothing.

Pepper spray didn’t work, either.

“That’s why it took long because it was so methodical,” Villanova says.

Finally, nearly 12 hours after it began officers cut out the suspect – 38-year-old Charles Estell — from an air duct.

“Ultimately, they found him where we thought we’d find him, somewhere tucked in a place where he thought he wasn’t going to be detected,” the police chief says.

oaklawn robber Oak Lawn Police Chief: Manhunt For Bank Robber Was Tense, Methodical

An armed suspect robs a Bank of America branch in Oak Lawn on Saturday. (FBI)

Police say Estell had made off with $100,000 after dropping from the ceiling and into the bank’s vault.

He’s set to appear in court Tuesday afternoon. He faces up to 20 years in prison if convicted.

Estell has an arrest history dating back to 1992 and has served time in prison, according to the Sun-Times Media Wire. Offenses for which he was convicted include carjacking and aggravated kidnapping.