The suspect has been linked to burglaries in 7 towns.
"They usually go straight to the bedroom for the jewelry, grab a pillowcase to put it in," said Chief Bryan Gurney of the Ridgewood Police Department.
Four homes in Ridgewood were hit in a matter of 3 days recently.
Cops in Hohokus, Ramsey, Hackensack, Montvale, Washington Township, Saddle River and other Bergen County towns are doing likewise, and asking neighbors too to be more vigilant.
Also, the police chiefs say, make sure someone collects your mail and newspapers if you're going to be away.
It's darker, sooner, so adjust the timers on your houselights, try not to look like the perfect house to hit.