The burglary was discovered after the homeowner, 78-year-old Arthur Robinson, came home after visiting with his grandchildren.
The thieves apparently went into the master bedroom and scooped up several wooden boxes from the dressers, including one in a green velvet drawstring bag.
That box contained the ashes of Arthur's wife, Nancy, who died of cancer in 2009.
"I just kind of went empty when I realized that was something that wasn't replaceable, of course," Arthur said.
Police suspect the burglars, who first cut through a porch screen and opened the lock on a window, had no idea they were stealing someone's remains.
"Most people keep their jewelry in their master bedrooms in wooden boxes and, if you are in a hurry, then you would just take what you can and look through it later," said Det. Jeffrey Lai of the West Windsor Police.
Nancy and Arthur Robinson were married for 50 years when she died. They had three sons together and 12 grandchildren.
Being burglarized is violation enough, but Robinson says having his wife's ashes stolen is an almost unspeakable invasion of privacy.
"To reach into the innermost part of the personal area and take something out? Our sons feel the same way, that mom got taken," Arthur said. "It's totally a family thing, it doesn't have any value or meaning to anyone else."
West Windsor police are appealing to the thieves who, by now have gone through the loot they took from the Robinson home and discovered the container of ashes.
Police had a message for the burglars.
"Don't just throw it out, let's facilitate it getting back to the hands of the victim. Let's bring Mrs. Robinson back," said Det. Matt Kemp. "It's almost like a 'no questions asked' thing.'
Arthur Robinson is hoping against hope that will happen.
"It's obviously very important, it means a lot to me."
Trenton Crime Stoppers offering up to $1,000 reward for return of the ashes. If you have any information, please call 609-278-TIPS (8477).