The trial of Baltimore Police Officer Caesar Goodson Jr., the van driver accused of second-degree murder in the death of Freddie Gray, resumed Tuesday morning with continued testimony from a string of witnesses, reports the Baltimore Sun .

First was Det. Michael Boyd, a member of the police department's Force Investigation Team that investigated the incident. Boyd, who first took the stand Monday, continued to walk prosecutors through a series of city surveillance videos that tracked Gray's 45-minute ride in the back of a police transport van through the city on April 12, 2015. One of those videos showed the van rolling through a stop sign, something Chief Deputy State's Attorney Michael Schatzow has referenced in alleging that Goodson gave Gray what's known as a "rough ride," or an intentionally turbulent transport.

Prosecutors, however, have not yet outlined their theory of the alleged rough ride in detail.

On cross examination, Boyd told Goodson's attorney Matthew Fraling that in his review of all of the surveillance video of the van, he saw no evidence of the van making an abrupt stop, start, or turn.

Boyd was the state's 14th witness since the start of the trial last Thursday. Following his testimony, prosecutors called a series of three witnesses, all to establish that Gray's blood was found in the back of the van.