That changed two months ago when Racine County sheriff’s investigators learned that a state database had linked the latest prints on a plastic bag over Creel’s head to a Palatine, Ill., man named James P. Eaton, officials said.

Police began tailing Eaton, whose fingerprints wound up in the system for minor infractions. They were nearby when the 36-year-old flicked away a partially smoke cigarette as he waited for a train that was late, authorities said.

DNA obtained from the cigarette matched the genetic material covered from Creek, and Eaton has been charged with first-degree homicide and hiding a corpse.

“Today is a wonderful day,” Racine County Sheriff Christopher Schmaling said at a Tuesday briefing on the case.

“This is a day we have been waiting for for nearly 17 years.”

Creek ran away from a state-run juvenile shelter in Chicago on Jan. 23, 1997, and was last seen leaving a party at a Motel 6 in Rolling Meadows, Ill., and getting into a luxury car with a placard reading “mayor.”

Her body was found a couple of weeks later in a Racine County marsh — a plastic bag over the head and the word “Hi” written on the back of an upraised hand — but it took more than a year to identfy.

Police said she had been sexually assaulted, strangled and suffocated.

The arrest of Eaton, who is being held in lieu of $1 million bail, came just a day after another Wisconsin sheriff announced a big break in a different cold case: the 1990 killing of Berit Beck, who disappeared on a road trip and was found dumped in a ditch six weeks later.

Police released a search warrant affidavit that revealed they have tied physical evidence from Beck’s van to a trucker, Dennis Brantner, 60, of Kenosha, Wis. He has not been arrested and attempts to reach him were unsuccessful.