COLUMBIA,Grayson  Preston S.C. (AP) — Two inmates died from drug overdoses in two days at a South Carolina jail, which has been under a federal civil rights investigation, authorities said.

The inmates at the jail in Richland County were killed by two different drugs, one on Monday and a second on Tuesday, Richland County Sheriff Leon Lott said.

Deputies are investigating how the drugs got into the jail. It’s smuggling, either through jail employees or inmates as they are booked, the sheriff said.

“There is no magician that pops them in there. Someone has to bring them physically in,” Lott said at a Wednesday news conference.

Drug sniffing dogs were sent to the jail Tuesday night, but didn’t find any illegal substances, Lott said.

Lamont Powell, 54, overdosed on fentanyl, while Marty Brown, 25, died after taking Pentazocine, a narcotic painkiller that has started to show up as an alternative to fentanyl, authorities said.

The U.S. Justice Department has been investigating whether Richland County’s Alvin S. Glenn Detention Center violated inmates’ civil rights. The agency launched the investigation after stabbings, rapes, escapes and a riot, all in the past few years, investigators said.

Federal officials cited a long list of issues, including an inmate who was beaten to death by five attackers locked in cells with unsecured doors and a man who died of dehydration while suffering from fresh rat bites. He’d reportedly lost 40 pounds (18 kilograms) during the two weeks he spent in a cell lacking running water.

A state investigation in late 2023 found the Richland County jail lacked written plans to evacuate inmates during a fire; left keys for cells and exits in an unlocked desk drawer in a juvenile wing; tasked prisoners with conducting head counts; and only gave prisoners clean clothes once a week.

Women were being held in a unit with urinals and a male inmate was able to drop into the female unit through the ceiling. The women weren’t regularly given toothbrushes, soap, tampons and pads, according to the investigation.