BOSTON – Keeping bombing suspect Dzhokhar Tsarnaev alive and able to answer questions would be a badly-needed intelligence coup for terror investigators, a former U.S. District Attorney told Yahoo News on Saturday.

“The fear of law enforcement has always been the small, insular cells that are kind of under the radar,” said Richard Roper, a federal prosecutor for 21 years. “Either the lone wolf or the small cells … they’re difficult to obtain intelligence on. I hope they get some good stuff out of him.”

On Saturday, Dzhokhar was reportedly clinging to life and under heavy guard at Beth Israel Deaconess Medical Center in Boston. He apparently suffered gunshot wounds to the neck and leg during separate gun battles with authorities on Friday.

Tsarnaev, 19, and his brother, 26-year-old Tamerlan Tsarnaev, are believed to have planted the two backpack bombs near the finish line of Monday's Boston Marathon. The twin explosions killed three people and injured 180 others.

Tamerlan Tsarnaev was killed early Friday in a fierce firefight with police in Watertown, a Boston suburb. Dzhokhar eluded capture for another 19 hours and was finally found hiding inside a boat in the backyard of a Watertown home. That's where he surrendered Friday evening after reportedly exchanging more gunfire with cops.

[PHOTOS: 'We Got Him': Covers capture bombing suspect's dramatic arrest ]

Roper, who retired in 2008 after four years as the U.S. attorney in the Northern District of Texas, predicted Dzhokhar would probably be charged in his hospital room sometime this weekend.

“Then when he’s better, he can make an appearance in court,” he said.

No motive has been revealed for Monday’s attack. The Tsarnaev brothers, who were born in the former Russian territory known as Kyrgyzstan and are of Chechen descent, lived in Cambridge for several years. Dzhokhar became a naturalized American citizen last year.

Hours after the FBI made a public plea to help identify the suspects from video and photos at the marathon, the brothers allegedly shot and killed a university police officer and wounded a transit cop. Authorities said the pair launched explosives during a dramatic high-speed chase in residential Watertown early Friday.

Story continues

Dzhokhar’s alleged string of destruction gives federal prosecutors many options, including the death penalty.

Roper, who put two people on federal death row, said many factors will be considered when it comes to deciding on capital punishment.

“Age, culpability, involvement in the planning and whether he cooperates are a few,” Roper said, adding that cooperation could be an intelligence windfall.

“To see if they are linked to other foreign terrorists or other terrorists that might be here,” he said.

[RELATED: Bombing suspect, uncle had falling-out over Islam]

Immediately after Dzhokhar’s capture, federal prosecutors stirred controversy in legal circles by refusing to grant Dzhokhar his Miranda rights against self-incrimination, citing public safety concerns.

“There’s a need to immediately question the guy whether you Mirandize him or not to save lives,” Roper said. “The question is how far do you go before it turns into a custodial interrogation?”

Republican Senators John McCain of Arizona and Lindsey Graham of South Carolina went a step further, suggesting Dzhokhar be treated as an enemy combatant like a soldier captured in war. The move drew the ire of longtime McCain aide and speechwriter Mark Salter.

“My friend, Lindsey Graham, is wrong on this,” Salter posted on his Facebook page. “However unforgivable his crimes, he's a US citizen, arrested on US soil, with, at this time, no known associations with foreign terrorist organizations at war with the U.S. To declare him an 'enemy combatant,' and deny him his rights is un-American.”