Demonstrators protest outside of the courthouse during the trial of Officer Caesar Goodson Jr., one of six Baltimore city police officers charged in connection to the death of Freddie Gray, during the third day of his trial, Monday, June 13, 2016, in Baltimore Md. Goodson, the wagon driver facing second-degree murder, manslaughter and other charges stemming from the death of Freddie Gray. Porter's trial in the Gray case ended in mistrial. He will be tried again in September. (AP Photo/Jose Luis Magana)

Demonstrators protest outside of the courthouse during the trial of Officer Caesar Goodson Jr., one of six Baltimore city police officers charged in connection to the death of Freddie Gray. (AP Photo/Jose Luis Magana)

Prosecutors have rested their case against a Baltimore police officer charged with murder in the in-custody death of a man whose neck was broken in the back of a police van.

The prosecution rested on June 15 in the case against Officer Caesar Goodson after calling Stanford O’Neill Franklin to testify as an expert on police training and practices. Franklin is a former commander of education and training for the Baltimore Police Department.

Franklin says Goodson missed opportunities to put Freddie Gray in a seat belt in the back of the van during several stops, instead of leaving him shackled on the floor. But under defense cross-examination, Franklin said officers have discretion “in extreme circumstances” and that regulations didn’t allow Goodson to enter the back of the van when he was the only officer there.

The trial is scheduled to continue June 16.