Washington ? Jose Padilla, the U.S. citizen who has been held without charges for two years as an enemy combatant, admitted that he planned to use natural-gas systems to blow up high-rise apartment buildings in the United States, U.S. authorities said Tuesday.

The Justice Department released a seven-page declassified summary of Padilla’s alleged al-Qaida activities, including meetings with several of the terror group’s senior leaders. The move comes as the U.S. Supreme Court prepares to release a decision in the Padilla case on whether a citizen can be held for so long without being charged with a crime.

The new information is unlikely to sway the court, legal experts said, as the justices probably have made their decision. Also, the case revolves around whether the government has the legal right to detain a citizen indefinitely, irrespective of the evidence against the person.

Deputy Atty. Gen. James Comey said he hoped the release of the information would answer public concerns that he often hears during his public appearances about Padilla’s lengthy detention.

“I very much wanted people to know what I knew about Jose Padilla to address those questions,” he said at a news conference. “Those are important questions, and I hope this information will inform those questions.”

The information was released “so that in the court of public opinion, people could better understand why we’ve done some of the things we’ve done,” Comey said.

Comey conceded that none of the declassified information could be used in a trial because Padilla wasn’t permitted to have a lawyer present during his questioning.

One of Padilla’s lawyers on Tuesday accused the government of violating Padilla’s constitutional rights.

“The government is trying Mr. Padilla in the media instead of in the courtroom,” said Andrew Patel, a New York attorney representing Padilla. “If the government has evidence he’s done something wrong, they should indict him and try him. They want to have a press conference and not a trial.”

Until now, the government had released only sketchy details about Padilla, alleging that he’d been developing plans to detonate a dirty bomb, a radioactive explosive.

The newly released document, based on military interrogations of Padilla and others, maintains that Padilla wanted to build a radioactive bomb or a nuclear device, but that al-Qaida leaders doubted he would succeed and recommended that he use natural-gas heating systems to blow up apartments.

New York City, Washington and Florida were mentioned as possible targets.