There is a theory that goes like this: If it walks like a duck and quacks like a duck and has a beak like a duck, it’s probably a duck. However, the Department of Homeland Security says an incentive program in effect in New York, and possibly elsewhere, is not a duck.

The program rewards agents of the U.S. Border Patrol with cash, extra vacation time and even Home Depot gift cards and may be associated with an increased effort to arrest illegal aliens. If so, there has been a downside: 277 of those arrested on immigration charges by Rochester agents – who are part of the Buffalo sector – were in the United States legally. They never should have been arrested.

The question is whether the incentive program has encouraged agents to become careless, or worse, in whom they arrest. The Department of Homeland Security says no. “No such practice of paid incentives and awards for specific human targets or enforcement actions has ever occurred within the Border Patrol, nor will it ever occur within the ranks of any [Customs and Border Protection] component,” it said in a statement. Translation: no duck here.

Others aren’t so sure. Families for Freedom, a New York-based immigrant advocacy group, and the New York University Immigrants Rights Clinic believe that the bonus program and the arrests are linked, and they have attracted the attention of Sen. Kirsten E. Gillibrand, D-N.Y.

In a letter to Homeland Security Secretary Janet Napolitano, Gillibrand wrote that a focus on arrest rates, “coupled with a policy of rewarding arresting agents with bonuses, casts doubt over the fairness of each arrest.” Agents might be more likely to employ discriminatory methods such as racial profiling to gain those benefits, she said.

Her concerns are plainly valid and, Homeland Security’s denial of a incentive system notwithstanding, the department refuses to say what the rewards are for, if not arrests. Translation: It still looks like a duck.

Considered in one way, a financial incentive program makes sense. Such enticements are a common and effective tool for increasing productivity. If Border Patrol agents were selling washing machines, such a program would be fine.

But it doesn’t work when the point is to deprive people of their liberty and threaten them with punishment. The temptation to cut corners can be great and the suspicion of it is inevitable. What is more, even taking Homeland Security at its word, there were 277 wrongful arrests without an incentive program. How much worse would it be if financial rewards were added into the mix?

Gillibrand and other members of Congress from New York need to demand clear answers from Homeland Security about what the incentive program is meant to accomplish and how 277 people came to be wrongfully arrested by its Rochester-based agents.

And, to be clear, if the program is indeed meant to increase the number of arrests made, it needs to be ended. Control of our borders is important and worthy of increased attention, but a program such as that cannot be tolerated.