Metro Atlanta area education leaders are cracking down on students who illegally cross district lines to attend other schools — combing through documents, questioning parents and surveiling students to see where they live, in an effort to stem millions of dollars in revenue loss.

Enrollment fraud, a growing practice that has districts putting more resources into policing it, involves students and parents lying about where they live. Some do it to attend higher-performing schools, while others want to play in successful high school athletic programs outside their attendance zones.

It costs Georgia school systems roughly $8,000 to $13,000 to educate each student. Local property taxes supply part of that cost, but districts don’t get that property-tax revenue for students who actually live elsewhere. Atlanta Public Schools pegs the cost to taxpayers for students who reside outside the city of Atlanta, for example, at $11,379.

The city of Decatur's school board recently approved hiring a full-time staff member to monitor enrollment fraud, with officials investigating 120 to 160 students per year suspected of lying about their residency to attend the fast-growing, high-performing school system. About 30 are asked to leave each year. However, officials believe a lot more are likely to be attending illegally.

In Fulton, school board members have have made proof-of-residency requirements more stringent. Fulton reviews more than 150 cases each year, officials say. Fulton and Atlanta have hired residency police officers who investigate enrollment fraud, and APS is considering more ways to eliminate it in the future, school officials say.

APS said it receives an average of 300 reported cases of enrollment fraud per year, and about 25 percent are founded. The district removes those students, sending them to the school where they live.

In DeKalb, Cobb and Gwinnett, it’s primarily left up to principals and administrators at individual schools to verify residency. Officials with those systems could not say how many enrollment-fraud cases they investigate each year.

School systems across the U.S. are putting more effort into stemming this growing practice – including hiring private investigators to spy on suspected fraudsters.

Education observers say the practice underscores the desperation felt by many parents, who want their children to attend higher-performing schools but may not be able to buy a house or live in more affluent neighborhoods with higher property taxes that typically have better schools.

“What you have are parents who happen to live adjoining to one of these quality school systems, and they want the best for their children, and they can’t afford it,” said Dan Domenech, executive director for national School Superintendents Association. “So what they do is try to figure out a way to get their child into that school system. Maybe they have an aunt or an uncle or a relative and they use that address as a way to get that child in the school system. But the child doesn’t actually live there.

“In a way, you can’t blame parents for wanting the best for their kids,” he added. “But at the same time, you have to understand it is theft of service. They are trying to get something for nothing in a way.”

Many school systems now require multiple documents, including utility bills, to prove residency, and require parents to sign an affidavit.

“What we found is some utility bills such as cellphones … that can be mailed to any address, people were using those a lot, and we were finding those weren’t actually the residencies,” said Chris Matthews, assistant superintendent of student support services for Fulton County. “So now it has to be, for example, a power bill, gas bill, water bill. You have to have some residency where the utilities are signed up for that address in your name.”

If parents are found to be lying, they can be fined or charged with a crime, though school systems in metro Atlanta say they don’t usually go that route. Instead, they remove the children from schools. Some districts in other states have brought charges against parents for lying about residency.

Caroline Truax, who has two children attending Fulton County schools, said she doesn’t condone lying about residency though she can see why some parents would try to get their kids into better-performing schools.

“I guess I could understand it but I don’t like the idea of anybody doing something that is not what the rules are saying,” she said. “I appreciate them (Fulton schools) doing their due diligence and respecting the taxpayers, their constituency basically.”

Under Georgia law, students are entitled to attend the school in the county where they live. Georgia does allow for school choice, but often when parents want to transfer their children to a better-performing school outside their zone, there’s a waiting list.

School districts in Georgia can legally charge tuition or fees to non-resident students (including students outside their attendance zone), but they aren't required to do so.

Student athletes' eligibility to participate in sports is determined by the Georgia High School Association. Students are immediately eligible at whatever school they start the ninth grade, no matter where they live. If a school system allows students to attend, the GHSA accepts the district's decision and rules the student eligible.

In early 2014, APS said it had discovered that 17 Grady High School football players, nearly a third of the team, had used fake addresses to play on the team and attend the school.

Players involved were forced to leave Grady, parents were billed for tuition between $5,000 and $35,000, depending on how long the students were improperly enrolled at Grady, and several school employees resigned or were suspended or reassigned. GHSA put Grady on probation for a season, made it forfeit its victories and barred it from the 2014 state playoffs. APS chose not to file criminal charges against the offending parents.

Families committing residency fraud also limit the number of spaces available fairly to all residents through the school-choice transfer process, school officials say.

Domenech, who heads the superintendents group, says residency fraud is becoming increasingly common in school districts across the country as the gap in wages widens and the percentage of children in poverty increases. He said the way education is funded in the U.S. needs to dramatically change to diminish that equity gap.

Currently about 45 percent of education funding comes from local property taxes, 45 percent from the state and 10 percent from the federal government.

“When you look at education across the world, it’s the opposite,” he said. “Most countries nationalize education. And so there’s a great deal of equity because a national government sets how much is going to be spent per child … The way we do it … continues to create tremendous inequity in education.”

“If you’re a wealthy community, you’re going to have the best schools. If you’re in an urban or rural setting, you’re going to have underfunded schools and not have the same type of quality … Until and unless we change the way we fund education, this (enrollment fraud) is going to continue to happen.”