The sentence imposed by U.S. District Judge Marcia Cooke marks another step in the extraordinary personal and legal odyssey for the 37-year-old Muslim convert, a U.S. citizen who was held for 3½ years as an enemy combatant after his 2002 arrest amid the "dirty bomb" allegations.
Prosecutors had sought life in prison, but Cook said she arrived at the 17-year sentence after taking into consideration the "harsh conditions" during Padilla's lengthy military detention at a Navy brig in South Carolina.
"I do find that the conditions were so harsh for Mr. Padilla ... they warrant consideration in the sentencing in this case," the judge said.
Cooke sentenced Padilla to less than the minimum usually according in such cases "because she was never fully convinced that the government had a strong case that directly linked Padilla to terror conspiracy as opposed to mere terror training," CBS News legal chief analyst Andrew Cohen says.
"Padilla may not feel like he got a break - 17 years or less for good behavior is no walk in the park. But it actually could have been a whole lot worse for the guy introduced to the world as the 'dirty bomb' suspect. He was looking at a life sentence as a maximum and 30 years as the suggested minimum and he got far less than even that," Cohen says.
Cooke also imposed prison terms on two other men of Middle Eastern origin who were convicted of conspiracy and material support charges along with Padilla in August. The three were part of a North American support cell for al Qaeda and other Islamic extremists around the world, prosecutors said.
The jury in his trial was told that Padilla was recruited by Islamic extremists in the U.S. and filled out an application to attend an al Qaeda training camp in Afghanistan.
Cooke said that as serious as the conspiracy was, there was no evidence linking the men to specific acts of terrorism anywhere.
"There is no evidence that these defendants personally maimed, kidnapped or killed anyone in the United States or elsewhere," she said.
Padilla was added in 2005 to an existing Miami terrorism support case just as the U.S. Supreme Court was considering his challenge to President Bush's decision to hold him in custody indefinitely without charge. The "dirty bomb" charges were quietly discarded and were never part of the criminal case.
Cooke sentenced Padilla's recruiter, 45-year-old Adham Amin Hassoun, to 15 years and eight months in prison and the third defendant, 46-year-old Kifah Wael Jayyousi, to 12 years and eight months. Jayyousi was a financier and propagandist for the cell that assisted Islamic extremists in Chechnya, Afghanistan, Somalia and elsewhere, according to trial testimony. Both also faced life in prison.
Padilla's mother, Estela Lebron, smiled at reporters in the courtroom when the sentence was announced and questioned outside the courthouse whether the Bush administration had misplaced its priorities in prosecuting her son.
"This is the way they are spending our money? Hello?" she said.
But she was also pleased he didn't get the maximum sentence. "I feel good about everything. This is amazing."
Attorneys for Hassoun and Jayyousi were also gratified but repeated that they will appeal their convictions and sentences, as will Padilla.
"It is definitely a defeat for the government," said Hassoun lawyer Jeanne Baker.
"The government has not made America any safer. It has just made America less free," said William Swor, who represents Jayyousi.
There was no immediate comment from the Justice Department or the Miami U.S. attorney's office.
The men were convicted after a three-month trial based on tens of thousands of FBI telephone intercepts collected over an eight-year investigation and a form Padilla filled out in 2000 to attend an al Qaeda training camp in Afghanistan. Padilla, a former Chicago gang member with a long criminal record, converted to Islam in prison and was recruited by Hassoun while attending a mosque in suburban Sunrise.
Padilla sought a sentence of no more than 10 years. Hassoun asked for 15 years or less and Jayyousi for no more than five years.
Padilla's arrest was initially portrayed by the Bush administration as an important victory in the months immediately after the Sept. 11, 2001, terror attacks, and later was seen as a symbol of the administration's zeal to prevent homegrown terrorism.
Civil liberties groups and Padilla's lawyers called his detention unconstitutional for someone born in this country.
Jurors in the criminal case never heard Padilla's full history, which according to U.S. officials included a graduation from the al Qaeda terror camp, a plot to detonate the "dirty bomb" and a plot to fill apartments with natural gas and blow them up. Much of what Padilla supposedly told interrogators during his long detention as an enemy combatant could not be used in court because he had no access to a lawyer and was not read his constitutional rights.
Padilla's lawyers argued for a lenient sentence, in part because of his minor role in the conspiracy that was the subject of last year's trial.
Attorneys for Hassoun and Jayyousi argued that any assistance they provided overseas was for peaceful purposes and to help persecuted Muslims in violent countries. But FBI agents testified that their charitable work was a cover for violent jihad, which they frequently discussed in code using words such as "tourism" and "football."