JACKSON, Miss. (NewsNation) — Authorities in Mississippi told NewsNation on Friday that they have not “ruled out” the possibility that four escaped inmates received help from someone on the inside.

“We’re still conducting the administrative investigation as well as the criminal investigation as well,” said Hinds County Sheriff Tyree Jones. “So we have not ruled that out. If we find that someone did help facilitate them from the inside, they will be held accountable.”

Jones had previously acknowledged security lapses and other concerns at the Raymond Detention Center near Jackson, Mississippi.

“We’re also reviewing our policies and procedures to see if there were any policies and procedures that were violated that could have helped facilitate this particular escape as well,” Jones said.

The Inmates

Corey Harrison, 22, was taken into custody Thursday at a home in Crystal Springs, about 20 miles from the prison.

Harrison and three other inmates escaped from the Raymond Detention Center near Jackson, Mississippi’s capital, on April 22, officials said.

Casey Grayson was found dead at a New Orleans truck stop over the weekend, officials announced earlier this week. His cause of death will not be determined until results from an autopsy report are returned. Investigators have not found any signs of foul play, Jones said.

Dylan Arrington died after barricading himself in a central Mississippi home and setting it on fire during an armed standoff with deputies on April 26. He is suspected of killing 61-year-old Anthony Watts and stealing his truck after the escape.

Jerry Raynes was arrested on April 27 after allegedly stealing a public works vehicle and fleeing to Texas.

The Associated Press contributed to this report.