(Oklahoma Department of Corrections/AP Photo)

Prompted by the botched execution of Oklahoma death row inmate Clayton Lockett, the ACLU today filed a lawsuit alleging that state prison officials violated reporters' First Amendment rights when they drew the shade nearly 30 minutes before Lockett's death.

"Because of the State's use of the viewing shade … the press and public received only government-edited access to an important government proceeding," the suit asserts.

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Lockett, 38, who was writhing on his gurney, "appeared to be in pain" before the blinds were drawn, the petition says. Afterward, sounds from inside the chamber "indicated pain and suffering," but journalists were "deprived of the opportunity to verify the nature and source of the sounds."

The drawn blinds also made it impossible for reporters to determine whether the state tried to provide medical care after the execution was called off, 10 minutes before Lockett's April death, according to the suit.

Filed on behalf of The Oklahoma Observer, its editor, The Guardian and a freelance journalist who covered the execution, the lawsuit asks the court to forbid the state from drawing the blinds prior to an official declaration of death.

The suit also asks for an injunction requiring state-made audio/video recordings of execution proceedings, including IV insertion, which might have been a factor in Lockett's death.

"When things go wrong, the state can't willy-nilly decide to close the proceedings. We're the public's eyes and ears," Oklahoma Observer editor Arnold Hamilton, a named plaintiff, said in a statement to ABC News. "The issue isn't whether you're for or against the death penalty. The issue is the public's right to know fully and completely how the death sentence is carried out, particularly whether it is being carried out in a lawful and humane way."

ACLU staff attorney Lee Rowland added in a statement that the state should not be allowed to "use … the execution shade like a Photoshop tool."

The Oklahoma Department of Corrections refused to comment, citing a policy against speaking about pending legal action.

The lawsuit comes on the heels of several problematic executions - and one judge's controversial suggestion that the justice system return to execution by firing squad.