A Utah judge on Tuesday declared federal sentencing guidelines cannot be constitutionally applied in a child pornography case, taking the lead in a national debate sparked last week by the U.S. Supreme Court.

"I take no pleasure in striking down the guidelines today . . . but the court's fundamental obligation is to uphold the Constitution," U.S. District Judge Paul Cassell said in declining to follow the guidelines implemented by Congress more than 15 years ago.

Though he was careful to say his decision applied only to the case at hand, Cassell later noted in a 39-page order the "potentially cataclysmic implications of such a holding."

Cassell first raised the issue Monday when he began issuing orders in each of his criminal cases advising prosecutors and defense attorneys of the constitutional questions brought about by the Supreme Court's ruling.

Cassell's courtroom was packed Tuesday with defense attorneys, prosecutors and law clerks — all anticipating some type of sweeping decision on the issue.

"It's a huge case," said defense attorney David Finlayson. "It really does have a wide-range effect on the (application) of the guidelines and it's going to be litigated, I'm sure, for a long time."

In his written order, Cassell announced he intends to continue issuing sentences without regard for the guidelines "until the constitutionality . . . has been definitely resolved by the Supreme Court." However, he said he will also issue a "fallback sentence" to avoid resentencing each defendant if the guidelines are ultimately found to be constitutional.

Thursday's ruling in Blakely v. Washington called into question the constitutionality of tens of thousands of sentences imposed under state and federal sentencing guidelines. The divided court held that judges cannot legally rely on facts not proven beyond a reasonable doubt to lengthen a defendant's prison term beyond that set out in sentencing guidelines.

Though the decision applied only to Washington state's sentencing guidelines, a dissenting opinion noted the similarity between that framework and the federal guidelines. Cassell, too, found the similarities too great to ignore.

"Doesn't the rationale also lead to the conclusion that the federal sentencing guidelines are unconstitutional?" Cassell asked Tuesday. "Isn't it time for the other shoe to drop?"

In light of the ruling, which Cassell wrote imposed a "constitutional straitjacket" on the court, the judge determined he had three options in sentencing Finlayson's client, Brent Croxford, on one count of sexual exploitation of a child.

First, he could convene a jury to determine the factors he would have previously used to enhance Croxford's sentence — that the South Jordan man obstructed justice by fleeing the state after being charged, and that Croxford participated in similar conduct with a second victim. Cassell dismissed that option as "essentially unworkable."