The American Civil Liberties Union warned Saturday that denying Miranda rights to Boston bombing suspect Dzokhar Tsarnaev is “un-American” and will make it more difficult to “obtain fair convictions.”

“Every criminal defendant is entitled to be read Miranda rights,” Anthony Romero, the ACLU’s executive director, said in a statement posted on the ACLU website.

On Friday night, an Obama administration official told NBC News that Tsarnaev would not be given a Miranda warning when he is physically able to be interrogated after receiving medical treatment.

Instead, the official said, the government will invoke a legal rule known as the “public safety exception,” which will enable investigators to question the suspect without first advising him of his right to remain silent and to be afforded legal counsel.

The exemption can be invoked when information is needed to protect public safety. In this instance, the government believes it’s vital to find out if Tsarnaev planted any other explosives before his capture or whether others might have plotted with him to do so, said the official, speaking on condition of anonymity.

The ACLU cautioned that the exemption “should be read narrowly."

“It applies only when there is a continued threat to public safety and is not an open-ended exception to the Miranda rule,” ACLU said in its statement. “Additionally, every criminal defendant has a right to be brought before a judge and to have access to counsel. We must not waver from our tried-and-true justice system, even in the most difficult of times.”

Tsarnaev is in serious condition and under heavy guard at a Boston hospital.

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