Baltimore cop testifies against officer in Freddie Gray trial
Officer Garrett E Miller is pictured in this undated booking photo provided by the Baltimore Police Department. REUTERS/Baltimore Police Department/Handout

A Baltimore policeman testified on Monday against a fellow officer charged in the death of black detainee Freddie Gray in the first testimony by another suspect in the high-profile case.

Officer Garrett Miller testified under prosecution questioning that he alone arrested Gray, whose death triggered rioting and protests in Baltimore in April 2015, without his accused partner Officer Edward Nero.

Prosecutors contend that Nero, 30, pursued Gray without probable cause and then failed to secure Gray in the van. But Nero's lawyers argue that he had little to do with Gray's arrest and never touched him except when he tried to help Gray find an asthma inhaler.

Asked in Baltimore City Court whether Nero had put handcuffs on Gray, Miller told prosecutor Michael Schatzow, "No, he did not."

Miller testified that he and Nero, a fellow bicycle officer, had no idea why Lieutenant Brian Rice ordered them to pursue Gray, 25, after he fled unprovoked in a high-crime area.

Nero, Rice and Miller are among six officers facing trial for Gray's death. He was bundled into a transport van while shackled and not belted in after officers found a spring-assisted knife in his pocket.

Gray died from a broken neck suffered in the van. The incident is one of those highlighted by the Black Lives Matter movement.

Miller and Nero have pleaded not guilty to misdemeanor charges of second-degree assault, reckless endangerment and misconduct. Nero waived his right to a jury and Judge Barry Williams will decide the case.

During cross-examination by defense lawyer Marc Zayon, Miller repeated that he was the officer who detained Gray. He testified that the responsibility for securing Gray in the van lay with the driver, Officer Caesar Goodson Jr.

Miller's testimony came after legal wrangling over prosecutors' efforts to force another officer, William Porter, to testify under limited immunity while his own charges were pending.

Maryland's highest court ruled in March that Porter had to testify. Forcing testimony in a co-defendant's trial was seen as unprecedented in Maryland.

Defense lawyers had argued against making Porter testify since it would allow prosecutors to compel other officers, such as Miller, to take the witness stand.

Porter's manslaughter trial ended in a hung jury in December. He is scheduled for retrial in September.

(Writing by Ian Simpson in Washington; Editing by Dan Grebler and Alan Crosby)