BAGHDAD (AP) – The U.S. will appeal a court decision dismissing manslaughter charges against five Blackwater Worldwide guards involved in a deadly 2007 Baghdad shooting, U.S. Vice President Joe Biden said Saturday.

Biden’s announcement after a meeting with Iraqi President Jalal Talabani shows just how diplomatically sensitive the incident remains nearly three years later. A lawyer for one guard, noting that word of the intended appeal came in Iraq, accused the Obama administration of political expediency and said the U.S. was pursuing an innocent man, rather than justice.

Blackwater security contractors were guarding U.S. diplomats when the guards opened fire in Nisoor Square, a crowded Baghdad intersection, on Sept. 16, 2007. Seventeen people were killed, including women and children, in a shooting that inflamed anti-American sentiment in Iraq.

Biden expressed his “personal regret” for the shooting and said the Obama administration was disappointed by the dismissal. “A dismissal is not an acquittal,” Biden said.

The U.S. rebuffed Iraqi demands that the American contractors face trial in Iraqi courts. After a lengthy investigation, U.S. prosecutors charged five of the contractors with manslaughter and took a guilty plea from a sixth. But the case fell apart when a federal trial judge in Washington, Ricardo Urbina, said in a Dec. 31 ruling that the Justice Department mishandled evidence and violated the guards’ constitutional rights. Prosecutors now face difficult odds getting an appeals court to reinstate the case.

The dismissal outraged many Iraqis, who said it showed the Americans considered themselves above the law. The Iraqi government began collecting signatures for a class-action lawsuit from victims who were wounded or lost relatives.

A lawyer for Blackwater guard Donald Ball, a former U.S. Marine from West Valley City, Utah, sharply criticized the U.S. government’s planned appeal. “By announcing this decision in Iraq, through an elected official, the United States makes clear it has decided to do what is politically expedient, rather than what is just based on Judge Urbina’s unshakable findings that the prosecutors engaged in gross misconduct and intentionally violated Mr. Ball’s constitutional rights,” attorney Steven McCool said in a statement. “In the end, the United States has shown it will pursue an innocent man, rather than justice.”

Messages seeking comment from lawyers for the other four guards who fought the charges were not immediately returned Saturday.

Those guards are Dustin Heard, a former U.S. Marine from Knoxville, Tennessee; Evan Liberty, a former U.S. Marine from Rochester, New Hampshire; Nick Slatten, a former U.S. Army sergeant from Sparta, Tennessee, and Paul Slough, a U.S. Army veteran from Keller, Texas.

The sixth guard, Jeremy Ridgeway of California, pleaded guilty to one count each of manslaughter, attempted manslaughter, and aiding and abetting. It’s unclear what Urbina’s ruling means for him.

Blackwater has said the guards were innocent, contending there were ambushed by insurgents. Prosecutors said the shooting was unprovoked.

Court documents paint a murky picture of a case rife with conflicting evidence. Some witnesses say the Blackwater convoy was under fire; others say it wasn’t. Some said the entire convoy fired into the intersection; others said only a few men opened fire.

Even the government’s key witnesses, three members of the Blackwater convoy, at times seemed to undercut the government’s case.

Since the shooting, the Myock, North Carolina-based Blackwater has renamed itself Xe Services and overhauled its management. Iraq has pulled the company’s license to operate in the country.