Minnesota- The last bastion of sin on a once-seedy strip of University Avenue is asking a federal judge to rule that a St. Paul law regulating adult businesses is unconstitutional.

R&R Books, where customers can browse and view adult videos, says the city's regulation of sexually oriented businesses should be thrown out because those businesses don't contribute to an increase in crimes such as prostitution.

To support their case, lawyers for the bookstore are pointing not only to a recent court decision involving a Minneapolis strip club, but also to the words of notorious St. Paul madam Rebecca Rand.

"There are just numerous ways this entire scheme is unconstitutional," said Randall Tigue, a lawyer for R&R Books. "It clearly is an unlawful restraint on speech."

The city of St. Paul has not yet responded to the arguments, and a lawyer for the city said he could not comment on a pending lawsuit.

The case began when the city tried to condemn the bookstore and two other businesses, including an adjacent liquor store, to make way for an office development. R&R Books is the last adult business near the intersection of Dale Street and University Avenue, once the site of the Faust and Flick adult theaters and the Belmont, a former strip club that now houses a police station.

R&R Books' dual use as a movie theater and bookstore is disallowed under city law, and Tigue first argued that the condemnation should be stopped because his client would not be able to relocate anywhere else in the city. The city tried working with the bookstore to relocate it, but those efforts have since been suspended.

Tigue has since broadened that argument, buoyed by a recent federal judge's decision involving 22nd Avenue Station in Minneapolis, a neighborhood strip club known as the Double Deuce.

Although free speech rights ordinarily protect such businesses, cities can regulate them if the city shows so-called adverse secondary effects - in other words, that the place contributes to crime and other neighborhood problems.

Cities often use studies linking the two to justify their laws, but Tigue pointed to another, more recent study casting doubt on the validity of the earlier work.

"All of the studies they rely on are crap," Tigue said.

In so many words, U.S. District Judge Michael Davis agreed. In April, he wrote that Minneapolis "cannot rely on shoddy, irrelevant studies to justify (the law's) passage."

Tigue is trying, in essence, to extend that ruling to St. Paul.

"I don't think St. Paul has any more evidence to support their ordinance than Minneapolis did," he said.

He has enlisted the support of Rand, a colorful St. Paul madam and advocate for legalized prostitution. Rand was sentenced to six months in jail in 1992 and ordered to pay a $200,000 fine - $172,000 of which she paid on the spot, mostly in 20-, 50- and 100-dollar bills. In an affidavit, Rand said that in her voluminous experience, prostitution is linked more to poverty than it is to adult businesses.

Davis' ruling was rare, and St. Paul can point to a 2002 U.S. Supreme Court case to defend itself. In that case, the court upheld a Los Angeles law targeting "dual-use" sex emporiums that is very similar to St. Paul's law.

The city is expected to respond to the suit next week. A July 25 hearing has been set before U.S. District Judge Ann Montgomery to decide the issue.