Newsday Makes Dubious Claim About Illegal Handguns

New York Newsday reported on a buyback in Nassau County, and how police paid up to $200 per handgun. The interesting part is the dubious reporting:

“A gun buyback program run by the Nassau County police department Saturday at a church in Rockville Centre was responsible for taking 173 illegal but operable handguns off the streets, police said.”

How do the police know – or the reporter for that matter – that these were “illegal” handguns? And does this mean that guns that were registered and legally owned couldn’t be turned in? That seems highly biased. So was this a case of bias in the buyback, or just biased (and inaccurate) reporting?