Baltimore police officers testifying in the trial of a colleague charged in a prisoner's death say officers rarely put seat belts on people they transport in the department's wagons.

The officers testified Thursday in the trial of William Porter, one of six officers charged in the death of Freddie Gray.

Officer Michael Wood told jurors that of the roughly 100 arrests he's been a party to, he's never belted in a prisoner or observed another officer buckling in a detainee.

Gray died on April 19, a week after his neck was broken in the back of a transport wagon. Prosecutors say Porter was criminally negligent for ignoring policy requiring officers to seat belt prisoners, and for failing to call a medic immediately after Gray indicated he needed aid.