WASHINGTON (AP) - Attorney General Eric Holder on Thursday rejected the notion that reading Times Square bombing suspect Faisal Shahzad his Miranda rights hindered investigators, telling Congress that Shahzad's cooperation is ongoing and that he has provided useful information.

Holder's assertions to a Senate appropriations subcommittee marked a sharp change in tone to the attorney general's recent appearances on Capitol Hill, where he has faced tough questions about his performance.

With what appears to be a success in the Shahzad case, Holder said that "we will continue to pursue a number of leads as we gather intelligence relating to this attempted attack." "Mr. Shahzad is in fact continuing to cooperate with us," has provided useful information and if convicted, faces a potential life sentence in prison, Holder said. "There is simply no higher priority than disrupting potential attacks and bringing those who plot them to justice," the attorney general said.

Separately, a senior U.S. intelligence official said that before investigators read Shahzad his rights, "they got what they needed." Chief among their check list of questions: finding out whether other imminent attacks were planned, or other operatives assisted Shahzad.

After nearly eight hours of questioning, investigators read Shahzad his Miranda rights, so whatever resulted from the subsequent questioning could be used in a future court case. Speaking on condition of anonymity because the investigation is continuing, the intelligence official said lessons learned in the handling of Christmas Day bombing suspect Umar Farouk Abdulmutallab case paid off, with a team being brought in immediately to handle the questioning and decide whether and when to read the suspect his rights.

The official credited this with producing the muted response from Capitol Hill, compared to the outcry from Congress over the handling of Abdulmutallab. The official called it proof the system they've now put in place works. At the Senate hearing, Sen. Barbara A. Mikulski, D-Md., did raise an issue that has come up in the Shahzad case - the fact that the suspect was able to get aboard an airliner before being arrested, even though investigators had already placed him on a no-fly list.

The issue "to me is like chalk on a blackboard," said Mikulski. Emirates airline apparently didn't notice the notification from the Transportation Security Administration that Shahzad's name had been added to the list, and Shahzad boarded the Mideast-bound jetliner before federal authorities pulled him off and arrested him.

On Wednesday, the government issued a new requirement for airlines to check the no-fly list more often, a move aimed at closing that security gap in future cases of terror suspects. "I suspect we would have detected him earlier" had the change already been in effect, Holder said, marking the one aspect of the Shahzad case on which the attorney general conceded a shortcoming.

Republican Sen. Lisa Murkowski of Alaska focused on the no-fly list problem in the apprehension of Shahzad, prompting Holder to declare that "I am never satisfied, even in an operation like this one" that was successful.

The arrest of Shahzad has provided an opportunity for the attorney general and the Obama administration to display a success in the fight against terrorism following Holder's ill-fated decision last year to put reputed Sept. 11 attack mastermind Khalid Sheikh Mohammed and four accused co-conspirators on trial in New York.

The White House stopped that effort. Democrats at the hearing praised Holder for law enforcement's performance on the Shahzad case. "It was pretty remarkable to see all the pieces come together," said Senate Judiciary Committee chairman Patrick Leahy, D-Vt.

Mikulski called it "amazing" that Shahzad had been taken into custody Monday night in such a short time after the Saturday evening bombing attempt. Holder cited an earlier thwarted plot to bomb New York City's subway system, in which a key participant, Najibullah Zazi, pleaded guilty to terrorism violations.

The Shahzad and Zazi cases reflect "exemplary investigative efforts" by federal agents, law enforcement officers and Justice Department prosecutors, the attorney general said in his prepared remarks.