Michael R. Huber, 32, of 2133 Ontario Drive, believes DNA evidence was obtained from him with an illegal warrant.
His attorney Tuesday asked a Rock County judge to suppress the evidence, claiming probable cause didn't exist for police to take Huber's DNA.
But Judge James Daley denied the request during a hearing in Rock County Court.
Huber is charged with six counts of first-degree sexual assault involving a weapon and one count of second-degree sexual assault of a child in two home invasions.
He is charged in a 1998 assault against a 27-year-old woman and a 2003 attack against a 13-year-old girl, according to the criminal complaint.
Huber is suspected of entering six homes and sometimes sexually assaulting women from 1998 to 2005, according to police.
Detectives believe one man committed all the crimes because of a distinct method of operation.
Huber threatened his victims with a gun in two incidents, according to the criminal complaint.
A partial fingerprint left at the crime scene of the 1998 attack was matched to Huber, according to police.
The fingerprint was used as probable cause for a search warrant to obtain Huber's DNA, which tied Huber to two cases, according to the criminal complaint.
Huber's attorney, Joshua Klaff, argued the search warrant lacked probable cause because a FBI analyst used the term "positive hit" when describing the link between Huber's fingerprint and the crime scene fingerprint.
Klaff said the word "hit" could have meant a hunch. He added that no details such as fingerprint "points of comparison" were in the warrant to establish probable cause.
But assistant district attorney Mary Bricco, argued the court used common sense when interpreting the term “positive hit” as a fingerprint match. She said a search warrant doesn't have to have detailed language to establish probable cause.
The judge decided the information in the search warrant was sufficient.
Huber remains locked in the Rock County Jail on a $160,000 cash bond.
His trial is scheduled to start Monday.