The arrest of the Boston Marathon bombing suspect has ignited debate over a "public safety" legal exception that allows police to interrogate individuals without reading them their rights.
A 1966 Supreme Court ruling requires that police read suspects their so-called Miranda Rights, in which suspects are told upon arrest that they have the right to remain silent and to an attorney.
If prosecutors want to use what a suspect says in police custody at trial, they must prove the individual was informed of his or her Miranda rights, understood them and voluntarily waived them.
However, the Supreme Court in 1984 ruled in favor of a "public safety" exception, in which police can interrogate a suspect without reading the rights if there is an active threat to themselves or to the public.
In a 2010 memo, US Attorney General Eric Holder noted that the "arrest of an operational terrorist may warrant significantly more extensive public safety interrogation than would be permissible in an ordinary criminal case."
Media outlets citing Justice Department officials say investigators have invoked the exception with regard to Dzhokhar Tsarnaev, 19, the suspected Boston Marathon bomber arrested late Friday after a massive manhunt.
Police may fear that Tsarnaev knows of hidden explosive devices or other terror plots that could endanger the public.
The Justice Department could not immediately be reached for comment, but US attorney Carmen Ortiz hinted at the exception at a press conference Friday.
"There is a public safety exemption in cases of national security and charges involving acts of terrorism. And so the government has the opportunity right now," she said.
Some Republican lawmakers have gone a step further, arguing that Tsarnaev, an ethnic Chechen who lived in the United States for a decade and reportedly became a citizen last year, should be declared an "enemy combatant," which is the same legal status of detainees being held at the Guantanamo military prison.
"A decision to not read Miranda rights to the suspect was sound and in our national security interests," reads a joint statement by Senators Lindsey Graham, John McCain, Kelly Ayotte, and Representative Peter King.
"However, we have concerns that limiting this investigation to 48 hours and exclusively relying on the public safety exception to Miranda, could very well be a national security mistake."
The American Civil Liberties Union meanwhile argued that the public safety exception "should be read narrowly" and should not be "open-ended."
"Every criminal defendant has a right to be brought before a judge and to have access to counsel," ACLU head Anthony Romero said in a statement.
"We must not waver from our tried-and-true justice system, even in the most difficult of times. Denial of rights is un-American and will only make it harder to obtain fair convictions."