"Even though the defaulters have vacated, the courts forced the banks to restart the foreclosure process, which added to the already high volume at the time," Frank said.
Zombies sit in all kinds of neighborhoods, among the well-to-do and the less well-heeled, local observers said. In some cases, said Carol McCann, of Re/Max Millennium in Somerton, many who received notices of foreclosure simply vacated, "assuming that the bank now owns the property."
At the height of the foreclosure crisis, sales of distressed housing outpaced all others, depressing prices and undercutting efforts by home builders.
This year in the Philadelphia region, said Charles Cosgrove of Educated Realty in Doylestown, there have been fewer sales of houses repossessed by lenders, and the number of short sales - in which the lender agrees to accept less than the value of the mortgage - is half what it was in 2013.
RealtyTrac's figures put zombies in the Philadelphia region at 6,101, fifth-highest nationally.
In theory, that many cut-rate houses could wreak havoc on a market still working its way back.
"If lenders put them all on the market for sale at once," it would drastically change property pricing, said Noelle M. Barbone, office manager at Weichert Realtors in Media.
That has little chance of happening, however.
"We have submitted good [purchase] offers to banks, but there is still way too much red tape to make anything move faster or get better," said Val Nunnenkamp, of Berkshire Hathaway Home Services Fox & Roach Realtors in Marlton.
Nunnenkamp said he knew of "12 to 14 houses that meet that [zombie] description, including one in Voorhees that's been vacant for four years."
In the case of another Voorhees house, he said, "we gave this bank six offers in 21/2 years, and plenty of other people were interested while the six offers were being negotiated and turned down."
RealtyTrac data show New Jersey in the nation's top five for zombies, with 12,170 statewide, up 58 percent year over year.
"It's difficult to distinguish between a foreclosure that was not completed vs. one that is working its way through [the state's] three-year timeline," said Michael Lentz, of Keller Williams Real Estate in Washington Township.
Most neighborhoods in his area have one or two vacant homes, Lentz said, and "my guess is there are several hundred throughout Gloucester County."
Patricia Settar, of BHHS Fox & Roach in Mullica Hill, said a colleague had the job of securing these properties, and "there are quite a bit."
"I've had buyers who want them, but I can't make it happen" because of lenders, she said. "Nice homes, and now they sit vacant and bring down values in the community."
Pennsylvania has 4,789 zombies statewide, RealtyTrac says.
Frank Dolski, of Coldwell Banker Hearthside in Lahaska, Bucks County, said zombie properties often sit as long as three years. In one case, in a "million-dollar neighborhood" in Buckingham Township, one property that has not been maintained has had an impact on the values of others.
"When the bank finally sells, the subject property will be tremendously affected," Dolski said.
Colmar attorney William D. Schroeder Jr. estimated he had 10 zombies in his client files.
"A number of my clients have surrendered them as part of a Chapter 7 [bankruptcy]," he said. "I notify the mortgage company departments and the companies do not move forward.
"I personally believe their inventory is just too large and they are understaffed," Schroeder said. "The properties sit there blighting the neighborhood. I advise my clients to take the minimum steps to secure the property and keep it safe from the elements and vegetation."
Donald Sepety of BHHS Fox & Roach in Collegeville has handled three zombies in the last two weeks, noting that these "are houses in the middle - two townhouses and a nice rancher."
Zombies are "all over the place," adding that he expects more to head for the market because the cost of keeping them on the lenders' books is rising as the properties' value sinks.
Sometimes, said Cheryl Miller of Long & Foster in Blue Bell, zombies "start as short sales that never make it to settlement," then are foreclosed. Months pass, and "finally they show up as bank-owned."
RealtyTrac said Wells Fargo had the most zombies - 18,695 nationally.
Wells Fargo spokeswoman Barbara Nate said it does not comment on "reports issued by third parties."
If a property is delinquent and vacant and has not yet gone to foreclosure sale, she said, Wells Fargo moves to complete the foreclosure quickly and maintain and secure the property in the interim.
She said the lengthy foreclosure timeline in certain areas "delays our ability to complete renovations to get many properties on the market and in the hands of new owners."
BY THE NUMBERS
Number of zombie homes nationally. These are homes
that have been vacated
even though foreclosure
has not been completed.
Zombie homes in Philadelphia, fifth most nationally.
Zombie homes in New Jersey,
up 58 percent year over year.
Zombie homes in Pennsylvania.