In Truro, Massachusetts, the police are stumped, according to the New York Times:

In an unusual last-ditch move to find clues to the three-year-old killing of a freelance fashion writer, police investigators are trying to get DNA samples from every man in this Cape Cod hamlet, all 790 or so, or as many as will agree.

[…]

Sgt. David Perry of the Truro Police Department and other law enforcement authorities here say that the program is voluntary but that they will pay close attention to those who refuse to provide DNA.

“We’re trying to find that person who has something to hide,” Sergeant Perry said.

Attempting a DNA dragnet out of frustration is one thing; that the cops will plainly tell the press that people who don’t ‘voluntarily’ cooperate with a search with no probable cause will effectively be suspects is the alarming thing here.