Even though the man suspected of detonating two bombs during the Boston Marathon has already received his Miranda rights, South Carolina Republican Sen. Lindsey Graham Monday continued to press for the suspect to be "interrogated" and treated as an "enemy combatant" for intelligence-gathering purposes. But Graham said the information gathered shouldn't be used in court because the suspect is a U.S. citizen.

Dzhokhar Tsarnaev, a 19-year-old naturalized U.S. citizen born in Kyrgyzstan, was charged Monday in federal court for last week's bombing, which he allegedly set off with his brother, Tamerlan Tsarnaev, 26. Tamerlan Tsarnaev was killed last week during a police search for the suspects.

The Justice Department has declined to treat Dzhokhar Tsarnaev as an enemy combatant, which would have allowed authorities to question him without an attorney present.

"I strongly disagree with the Obama administration's decision to rule out the enemy combatant status for the suspect at this time. I believe such a decision is premature. It is impossible for us to gather the evidence in just a few days to determine whether or not this individual should be held for questioning under the law of war," Graham told reporters Monday during a press conference on Capitol Hill. "The last thing in the world we should do in the times in which we live is to limit our ability to gather intelligence to the criminal justice system. In essence, you will have turned over the intelligence-gathering process to the accused and their lawyer."

Graham said evidence was "ample and overwhelming" to him that the attacks that left three dead and more than 200 injured were "inspired by radical Islamists." He said it would be appropriate to gather as much intelligence as could be obtained about the man's possible connections with international terror groups before reading him Miranda rights while in custody. Any information collected, however, would not be used for the criminal case, he added.

"No criminal defendant should ever be required to incriminate themselves in a criminal case," Graham said. "Every nation at war should have the ability to defend themselves by gathering intelligence. These are not mutually exclusive concepts."

Tsarnaev was given his Miranda warning Monday afternoon, after Graham made his comments.