The 21-year-old man accused of killing nine people at a historically black church in Charleston is being held in a cell next to the former North Charleston police officer who fatally shot a black man running away from him.

Charleston County sheriff's Maj. Eric Watson said Friday that Dylann Roof, who is accused in the church shooting, is in a cell next to former officer Michael Slager.

Slager has been charged with murder in the death of Walter Scott. Slager's shooting of a fleeing Scott following a traffic stop on April 4 was recorded on a bystander's cellphone.

Roof has been charged with nine counts of murder. He is being held in cell 1141B. Slager is in 1140B.

Each is alone is his cell. It's unlikely the two can talk to each other.

The Associated Press contributed to this report.