Prosecutor Michael Schatzow alleged in his opening statement that Baltimore police officer Edward M. Nero ignored department regulations and police training in the arrest and detention of Freddie Gray, as Nero's trial began Thursday.

Baltimore Circuit Judge Barry G. Williams is hearing the case after Nero chose to have a judge rather than a jury decide his case, reports the Washington Post .

Nero, Schatzow said, made no attempt to find out why Gray was being arrested and, after Gray was placed in a police wagon, did not put a seat belt on him as required by department rules. His actions "went against all of his training," Schatzow said.

Nero, one of six Baltimore police officers facing charges in the case of Gray, showed no reaction as he listened to Schatzow. The second officer to go to trial in the case, Nero is facing four misdemeanor charges — second-degree assault, reckless endangerment, and two counts of misconduct.

In his opening statement, Nero's attorney, Marc Zayon, said his client did everything correctly in the chase and apprehension of Gray.

If convicted, Nero could face up to 10 years on the second-degree assault charge and five years on the reckless endangerment charge.