Law enforcement authorities say they need more tools to fight child sexual abuse and help put sexual predators behind bars.

Amendment 2, which will be on Missouri election ballot Nov. 4, gives prosecutors and law enforcement officers the help they need.

The proposal would amend the state constitution to give judges the discretion to allow previous acts of sexual violence against minors to be disclosed in court. The federal government and nearly all other states allow juries to learn whether a defendant in a child sexual abuse case may have been accused of similar crimes in the past.

The only reason Missouri doesn’t is because the state Supreme Court struck down a law in 2007 that allowed evidence of past sexual crimes to be used against people facing sex-related charges involving victims younger than 14.

“Evidence of a defendant’s prior criminal acts, when admitted purely to demonstrate the defendant’s criminal propensity, violates one of the constitutional protections vital to the integrity of our criminal justice system,” the court ruled.

Amendment 2 has been narrowly tailored to require a judge’s permission to admit evidence of prior relevant criminal acts, even if a defendant was not charged. It also stipulates that it can be used only in child sex abuse cases.

In most criminal cases, admitting evidence in prior cases that did not result in charges would be considered unfairly prejudicial. But in child sexual abuse prosecutions, there are significant reasons to allow such evidence to be admitted.

Among them:

• The crimes are nearly always committed in secret, and only the victim and the perpetrator know what happened. There are usually no other witnesses available to help a prosecutor make his case.

• Victims are often too young, too immature or too traumatized to provide compelling testimony.

• The crime is frequently reported long after physical evidence has disappeared or deteriorated.

• Past victims often come forward once a prosecution is underway.

The Missouri Association of Prosecuting Attorneys, the Missouri Police Chiefs Association and the Missouri Sheriffs Association are among the groups that support the amendment.

Even if just one part of this problem was improved by allowing the admissibility of such evidence — that young children could be spared the trauma of having to relive their abuse in a courtroom — it would be reason enough to recommend supporting Amendment 2.

The rest of what the amendment does provides even more reason to merit a yes vote. Those who commit crimes in secret against society’s most vulnerable victims should not be able to keep their past a secret. This amendment seeks to level the playing field for prosecutors. Vote Yes on Amendment 2.