The city of Houston is turning to an unusual source to help fund rape investigations: strip clubs.

The City Council passed an ordinance Wednesday that requires strip clubs to pay a $5-per-visitor fee to help pay for the analysis of biological evidence collected from rape victims in hopes of identifying their attackers.

Police in Houston, and in many other parts of the U.S., lack the money to promptly analyze evidence such as hair particles and blood specimens, gathered by investigators in packets known as rape kits. Houston estimates it has 6,000 rape kits that have yet to be scrutinized by crime laboratories.

Supporters of the ordinance, which was supported by Mayor Annise Parker and approved on a 14-1 vote, contend that strip clubs should shoulder some of the costs of rape investigations because the establishments can cultivate unhealthy attitudes toward women that can lead to sexual assaults.

"There are negative secondary effects associated with adult-entertainment establishments," said Ellen Cohen, the council member who championed the ordinance, which could generate up to $3 million in annual revenue.