JEFFERSON CITY - A call from an abused child's mother is the story behind one of the issues on Missouri's November ballot.

The call involved a child who had been sexually abused.

But no one was convicted of the crime because there was not enough concrete evidence to convict the perpetrator.

This call spurred one St. Louis legislator to sponsor legislation that has made its way on to Missouri's ballot

If passed, Amendment 2 would allow prior criminal history to be used as evidence in a case of child sex abuse.

Rep. John McCaherty, R-St. Louis County, sponsored the legislation in 2013.

"The man had actually groomed this young lady for sexual abuse," McCaherty said.

However, the prosecutor determined there was not enough evidence of the actual act of grooming to file charges. 

If the constitutional amendment on the Nov. 4 ballot is approved, criminal history, regardless of whether charges were dropped or how long ago charges were filed, could be used as evidence in state child sex crime cases.

Critics of Amendment 2 said this kind of evidence removes the burden of proof for the state during a trial and unfairly focuses on a defendant's character.

"The purpose of propensity evidence is to allow a jury to consider the type of person someone is rather than holding the state to their burden of proof beyond a reasonable doubt," said Michelle Monahan, a veteran public defender and secretary of the Missouri Association of Criminal Defense Lawyers. According to Monahan, "[Propensity evidence] is truly the bell that cannot be un-rung."

But McCaherty said it would be up to the judge to decide what criminal history is relevant to the case being argued, ensuring a defendant's right to a fair trial.

"All of us want the trial to be fair and right now, it is absolutely not fair," McCaherty said. "In fact, it's in favor of the one that committed the crime."

McCaherty said that federal law allows this kind of evidence to be used in cases of child sex abuse. Monahan said that this kind of evidence is only admissible under certain circumstances.

Another criticism of the amendment is the highly sensitive and emotional nature of child sex abuse cases, both for the victim and the accused.

"Within this subject matter, the only thing that's worse than being the perpetrator is being falsely accused," Monahan said. "It's a life-destroying situation."

Some legislators voiced concerns that the amendment goes too far in terms of prosecuting the accused, depriving individuals of a fair and balanced trial. That's why lawyer and Sen. Joe Keaveny, D-St. Louis City, voted against the legislation.

"We're throwing the whole thought of a fair trial out the window," Keaveny said. "I won't say we're overreacting to a serious problem, but maybe we aren't addressing it in the most efficient way that we should."

McCaherty said the legislation is "a critical decision the state needs to make," when it comes to protecting victims of abuse from enduring additional trauma and having to face their abuser.

"For you or I, that's one thing," said McCaherty. You and I can sit before a jury and describe what's happened to us. For a child, that's a completely different story."

Monahan said that it is understood that children are delicate and need to be handled with care in these cases, but that current law already makes sure they are protected.

According to Monahan, the introduction of prior acts in child sex crime cases put jurors in an unfair position to have to know legal exceptions, especially since individuals related to prior acts aren't called to appear in court.

"So now you have a trial within a trial," said Monahan. "It's simply too much to ask of jurors to be able to distinguish this. These are the most complicated cases to prosecute and defend."