One of the wonderful aspects of a career in teaching is the opportunity it provides to change the life of a child.

Unfortunately, the influence teachers have over students also can give them an opportunity to change a child’s life for the worse.

A vivid example of such a case was reported in Monday’s Journal-World. A 25-year-old teacher in Lexington, Neb., is accused of fleeing to Mexico with a 13-year-old student in search of a romantic liaison. The two left the country after police began investigating an alleged intimate relationship between teacher and student.

The tragic kicker to this story is that the 13-year-old student is Mexican and had immigrated to this country illegally. Now, officials say, he has been turned over to relatives in Mexico and may not be allowed to return to his family in the United States.

Talk about changing a youngster’s life forever. Before becoming involved with this teacher, the student was just one of thousands of immigrant children being educated in the United States. This teacher’s poor judgment may have cost this student not only his home, but a chance at a better life in the United States. The teacher also faces serious charges, including kidnapping, child abuse and federal charges of transporting a minor across state lines or a foreign border for sexual activity.

It’s hard to understand what a teacher is thinking when he or she pursues a sexual relationship with a student, but such cases seem to be coming to light more and more. A recent Associated Press investigation found 2,570 educators had lost their teaching credentials between 2001 and 2005 following allegations of sexual misconduct. About 80 of those were in Kansas.

The AP documented troubling cases in which teachers dismissed because of such allegations were able to move from one district to another, sometimes several times, without detection. It’s understandable that districts can’t predict such behavior in advance but to sweep it under the rug after it occurs is unconscionable.

Efforts to shed light on this problem often have met with opposition, especially from teachers unions, which makes little sense. Teachers, above everyone else, should be concerned about the ethical reputation of their profession. As with any profession, the actions of a few can easily sully the reputations of many. Educators certainly have rights, and teachers accused of sexual misconduct deserve due process, but teachers should be at the head of the line when it comes to trying to rid their profession of people who take sexual advantage of immature students.

Schools have instituted “zero tolerance” policies for such things as bringing weapons or drugs to school. There could be no better target for a “zero tolerance” policy than for teachers who become sexually involved with students.