Suicide watch usually lasts just one or two days, said Jack Donson, a former correctional treatment specialist for the Federal Bureau of Prisons.
"I've never seen in my entire career a suicide watch lasting more than a week," Donson said. "So the context of him committing suicide while on watch, that's just a fallacy."
Donson said a suicide watch means an inmate is being monitored by a staff member 24 hours a day -- "three shifts of overtime people."
He said resources are limited, and overtime can be costly.
"I was probably being paid $500, $600 for a shift of overtime just to watch somebody through a window," Donson said.
If an inmate doesn't appear to be a threat to himself during suicide watch, he's removed from constant monitoring.
But Democrats and Republicans alike wonder whether Epstein's suicide could have been prevented.
"It's ridiculous that he was taken off suicide watch," said former New York Mayor Rudy Giuliani, who is now an attorney for President Donald Trump.
Democratic presidential candidates such as Sens. Kirsten Gillibrand and Elizabeth Warren say they want investigations. And Sen. Ben Cardin said he wants the results of the investigation to be made public.
"It's very hard to understand how he was not on a suicide watch," Cardin said.