A Riverdale condo complex plans to use DNA testing on dogs to figure out which of its residents aren't cleaning up after their pets — apparently the first in North Jersey to do so.

In a recent letter to residents, the management of the Grande at Riverdale said dogs' mouths will be swabbed for DNA. That way, any droppings found on the property can get the "CSI" treatment and be traced back to the pet owners who aren't taking care of business.

The letter cited a "small percentage of residents who have not been doing their due diligence."

Management plans to test dogs on Saturday or by appointment. Dog owners face a $100 fine if they don't bring in their pets for the testing by Nov. 1.

Afterward, any waste found on the property will be tested. Penalties will be stiff: Owners will face a $250 fine for the first offense, $500 for the second, and $1,000 for subsequent offenses.

The Grande is using PooPrints, a DNA-matching service provided by BioPet Vet Lab of Knoxville, Tenn. Eric Mayer, a company spokesman, says BioPet created PooPrints in 2010 after one of its scientists came to work fuming because she had stepped in dog waste.

"I want to know who did this," she said, according to Mayer. Since then, he said, the business has grown rapidly.