Slipping into a stealth mode and trying not to look conspicuous as they walk or drive through nearby residential neighborhoods, the special unit that includes school attendance officers and administrative staff conduct an unusual stakeout duty. Their prey isn’t an armed suspect, a runaway child or even a truant teen.

"We go out to try to confirm that the students that attend the public schools in Montclair actually live in Montclair as required under the law," said Bruce Dabney, assistant to Schools Superintendent Frank Alvarez.

Despite state laws that require children to attend the public school system in the municipality in which they reside, authorities say thousands of students statewide are attending public schools illegally. Officials say many who live in the so-called Abbot Districts are fleeing bad schools in urban areas and are seeking a better education elsewhere, usually in surrounding suburban towns.

Others are simply trying to skirt the law and continue to claim residency in municipalities that they have been forced to leave due to the municipality’s high cost of living. A growing number of children are finding themselves caught up in family breakups which force them to spend time with separated parents who live in different municipalities.

"We take this issue very seriously," said Alvarez, who recently completed a grueling round of budget deliberations that forced officials to make more than $1.5 million in cuts in proposed programs and staff positions. Alvarez said hard-pressed taxpayers want officials to account for every dollar of public funds they spend.

Each September, Dabney’s staff culls through the lists of district’s 6,500 students attending kindergarten through 12th grade, and conducts more than 900 random address checks beginning with the start of the new school year in September. These verifications continue throughout the school year.

"When mail we send to a home address comes back to the Board of Education as undeliverable, that sends up a red flag," Dabney explained.

Officials may decide to follow up with a personal visit to the home address. They may also ride public transportation or follow suspected out-of-district students by car after school. So far this year, more than 50 out-of-town students have been weeded out of Montclair’s 11 public schools.

In recent years, the number has exceeded more than 80 students each year.

Rising property tax rates and cutbacks in state aid to local education — coming at a time when the mortgage meltdown and soaring oil prices have the national economy is headed for a slowdown — are forcing local educators to carefully monitor their day-to-day operating costs.

Having out-of-town students taking up classroom seats can run up the public costs very quickly.

Dana Sullivan, the district’s business administrator, said Montclair’s public schools spend an average of $8,700 a year to educate children in Pre-K and kindergarten programs to as much as $11,100 for Montclair High School students.

The cost for students in special education programs can range between $11,900 to nearly $24,000 a year.

"Any way you look at it, it’s not fair to the residents of Montclair to send children to a public school here if you aren’t a resident," Dabney said.

With its highly regarded magnet school system, Montclair has enjoyed a reputation for providing a wide variety of educational programs for youngsters throughout its K-through-12 system. The quality of the Montclair public schools have long been a key selling point for the township.

"The magnet system and the strong special education programs are also a draw for the out-of-district student," Dabney explained. "But we’re also seeing divorces, joint custody arrangements, and other family situations as well as economic hardship play a role.

"It’s not uncommon for a family that is living in Montclair in the summer and early fall on a month-to-month lease, run into financial problems that forces them to move to another town and live with another family member or in a less expensive apartment," Dabney said. "Often, those families still continue to send their children to Montclair schools even though state laws require that you attend the public school in your town."