WASHINGTON – Missouri’s senators want to close a legal loophole they say allowed a Missouri judge to throw out a conviction of a sexual predator.

Sens. Kit Bond [pictured] and Jim Talent, both Republicans, introduced a bill Thursday that makes it a crime to solicit sex online from a minor even if the person solicited is an undercover agent over 18.

The move is a response to the case of Jan P. Helder, a Mission Hills, Kan., attorney accused of using an Internet chat service to solicit sex from someone he believed to be a 14-year-old girl.

A federal jury convicted Helder, 42, but U.S. District Judge Dean Whipple in Kansas City threw out the verdict last month, saying Helder could not be guilty because the person he communicated with online was actually an undercover Platte County detective.

Whipple’s decision outraged children’s advocates who worried it could curb the success of such Internet stings. Undercover agents typically pose as minors, waiting for sex offenders to make contact and arrange in-person meetings.

“This may in the minds of predators create a loophole and I think we should try and plug that loophole as quickly as possible by any means possible,” Talent said.

Don Ledford, a spokesman for U.S. Attorney Todd Graves in Kansas City, said the government plans to appeal Whipple’s decision. Ledford said the office would have no other comment on the decision or the legislation because the case is pending.

At least four federal appeals courts have rejected the type of defense used by Helder, but those decisions are not binding on Whipple. The 8th U.S. Circuit Court of Appeals, which covers Missouri, has not yet addressed the issue.

Under the change proposed by Bond and Talent, federal law would expressly provide that communicating with a law enforcement officer pretending to be a child is not a defense. Such language is already included in state law in Missouri.

“If there is a hole in the law that needs to be fixed in order to protect our children from predators, we must act now,” Bond said in a statement.

Kansas Rep. Jim Ryun has written a letter urging the Justice Department to appeal Whipple’s ruling, saying it is contrary to a number of other court cases.

“If permitted to stand, the practical impact of such a ruling would have devastating consequences for prosecutions of child predators who troll the Internet looking for children to entice and ultimately harm,” Ryun said in the letter.