In a major blow to prosecutors, a McHenry County judge today threw out evidence against a Schaumburg man accused of hiding a powerful bomb in his estranged wife's basement.

Judge Joseph Condon ruled the search that found a two-pound bomb in the Cary home belonging to Dominic Bender's wife was illegal.

"Any evidence based on that arrest can't be used at trial," said Assistant State's Attorney Nichole Owens, head of the criminal division.

Today's ruling could lead prosecutors to drop charges against the 28-year-old Bender.

"We are evaluating the case to determine whether we have enough evidence to proceed," Owens said.

The prosecutor said the state's attorney's office would decide whether to pursue the case by Bender's next court date on Aug. 20.

The discovery of a bomb in the Cary home of Bender's wife on Nov. 16, 2006 prompted authorities to evacuate surrounding homes and cancel classes at nearby Prairie Hill School.

Police searched the Cary home after finding guns and homemade firecrackers at Bender's Schaumburg home.

Because a Cook County judge ruled the Schaumburg search was illegal, Condon today ruled the later search in Cary - which was based on evidence found during the earlier search - also was illegal.

Bender faces three felony weapons charges and a misdemeanor reckless conduct charge in connection with the bomb found at his estranged wife's home.

In April, prosecutors in Cook County dismissed charges against Bender stemming from the illegal search of his Schaumburg home.