Somebody named Matthew J. Hartigan apparently stiffed the city out of years of taxes on a property he owned in Northeast Philadelphia. Or maybe he didn't. Truth is, it's hard to say for sure.

Matthew J. Hartigan of Clearwater, Fla., wants everybody - or at least those with authority to clear his name - to acknowledge that he, at least, doesn't owe the city a dime.

Not the $7,323 that one Philadelphia law firm demanded this spring in delinquent city and school district taxes dating from 1997. Not the $31,783 that same firm demanded in May 2012, wrapping in penalties, interest, costs, and attorneys' fees. Not the $12,228 dating to 1986 that a different firm demanded a decade earlier. And certainly not the $98,293 judgment a local bank demanded after pushing the property into foreclosure in 1998 - a judgment that Hartigan first discovered when it showed up on a credit report.

Hartigan doesn't question whether somebody owes those debts. He wants to know why he's been dogged for 17 years over debts that aren't his.

How can he prove that? For one thing, he was 12 in March 1972 when his namesake paid $2,500 for the property on Kinsey Street in Frankford - too young to sign a bill of sale.

Plus, he's never lived in Philly or anywhere nearby.

It's hardly surprising that there are multiple Matt Hartigans. I've got a pretty uncommon name, and there are multiples of mine, too. The question is why this Matt Hartigan got trapped in a story that's part Kafka, part Dada, and part Groundhog Day.

Hartigan has repeatedly staved off the collectors. But, like the Bill Murray character who keeps on reliving a mini-disaster, Hartigan can't make his successes stick.

"This is the third time in twelve years I have had to prove to someone in Philadelphia that you are not entitled to my money," he wrote to one of the law firms in 2009.

A former legal assistant, he wrote that he'd found five other Matthew Hartigans in the Social Security Death Index, including one in Pennsylvania who died months after the Frankford property was purchased.

Hartigan also noted there were five Michael Nutters and dozens of people with the same names as the city's revenue commissioner and collections manager - all of whom Hartigan copied on the letter, though none replied.

True to form, he was dunned again in 2011, this time for $2,274 on behalf of the city's Water Department, and again in 2012 and this spring.

Once again, it looks as if Hartigan has beaten the rap. Sharon Humble, a lawyer at the latest firm to demand he repay some other guy's debts, told me Clearwater Matt had repeatedly been fingered as Frankford Matt by a third-party "skip-tracing" company. Now his address has been flagged as wrong.

"We appreciate your patience and we expect you will not receive further correspondence from our firm," she told him in June.

Hartigan was reluctant to accept that - for good reason beyond his own experience.

Debt-collection complaints have topped all other complaint categories since the new Consumer Financial Protection Bureau began accepting them two years ago. Among more than 163,000 the CFPB has so far received, the most common problem is consumers who say they're being targeted for debts they don't truly owe. (To submit a complaint, call 855-411-2372 or go to ConsumerFinance.gov.)

For another perspective, I contacted Jim Francis of Francis & Mailman, a Philadelphia law firm that specializes in unraveling persistent problems in financial records - especially at the Big Three credit bureaus, Experian, Equifax, and TransUnion, but also at hundreds of other "consumer reporting agencies" that collect data on details such as job histories, insurance claims, and medical-payment records.

I shared a discovery of my own: When I did a national search for "Matthew J. Hartigan" in the LexisNexis public records database, Matt-from-Clearwater was the second of 43 hits. The second and third addresses listed for him were 1834 and 1836 Kinsey - the addresses linked to the errant debts. LexisNexis linked him to those addresses from March 1972 to last year.

The bad news is that aside from how long Hartigan's problem has persisted, Francis said his complaint was typical of hundreds he's handled over the years. Some clients have had pay garnisheed, or been blocked from getting mortgages or car loans, much as if they were victims of identity theft. But the flaw in these cases isn't a bad guy. It's a bad system.

"Somewhere, deeply embedded inside somebody's computer system, the wrong consumer is identified," Francis said. "You have to untangle it like a knot in fishing line."

The good news is that a firm like Francis' doesn't need to charge fees to consumers. If Francis wins, he can collect from companies that mishandled sensitive data.

Hartigan also can request a free report from LexisNexis, under the same rules that require the Big Three to provide free reports at www.annualcreditreport.com, at personalreports.lexisnexis.com or by calling 866-868-9534.

But be warned: The true origin of an error might not be clear from a report. Often, it takes a lawsuit to find that out.

215-854-2776@jeffgelles

www.philly.com/consumer