To our knowledge, The Sun's newsroom staff has received no special training in tax assessment and record keeping, yet reporters armed with no more than foot leather and personal computers seem to have a gift for uncovering gross errors — more charitably known as "discrepancies" — in Baltimore's property tax records.

First, it was the abuse of the Homestead Tax Credit, both legal and not, that has likely cost the city substantial sums in tax breaks given to properties that weren't eligible for the cap on assessment increases. The latest incident, uncovered by Sun reporters Scott Calvert and Jamie Smith Hopkins, involves three Federal Hill row houses that were turned into one — but which continue to be assessed (and reassessed) at a fraction of their combined value.

First, let's all agree that the owner of the Montgomery Street property appears to have done nothing wrong. He invested in his home and in the city, commendable actions. And he paid the property tax bills he was sent. It's the responsibility of the Maryland Department of Assessments and Taxation to revise its estimate of the property's value to reflect improvements, and it had the tools to do so.

Even this particular error in and of itself is not bankrupting the city. The end result was a loss of about $10,000, the result of taxes applied to a home valued at $552,000 instead of its actual value, likely $945,000 or more.

But the more troubling question is: How often is this happening in Baltimore and elsewhere? How badly does the agency miss the mark? And what is the net effect on the city and Maryland's 23 other subdivisions that rely so heavily on property tax revenue to finance public schools and other responsibilities of local government?

This much is clear: Nobody can answer those questions definitively. But surely even the staunchest defender of the Department of Assessments and Taxation has seen enough to have doubts about the accuracy of tax records. Those who earn a living helping Marylanders appeal property tax assessment decisions certainly have enough horror stories to tell.

But before anyone goes off half-cocked and calls for heads to roll, it should also be noted that some of these problems may simply be endemic to assessments. Is the state agency performance really any worse that that of its peers?

A major part of the problem may simply be a lack of manpower. The department has far fewer assessors today than it did a generation ago, although they have many more properties to track. Baltimore, for instance, has 23 assessors, with 237,000 properties to evaluate every three years. No matter how well integrated the databases of assessments, building permits and other information are, at some point, property assessments come down to a person periodically visiting the site and looking it over.

So which is it — is the agency inept or overburdened? Or are these errors just a normal part of doing business and might even prove to be a wash for state and local government (with the mistakes benefiting and penalizing property owners splitting somewhere close to even)?

As Robert E. Young, the agency's director, has pointed out, a recent analysis by the Council on State Taxation rated Maryland best in the nation for fairness of assessments. Historically, assessments have generally fallen at least slightly short of market value, a pattern property owners seem to appreciate and would be loath to give up.

Lawmakers in Annapolis can, of course, grill Mr. Young and his agency's performance, but that's obviously not enough. The real solution would be to produce an independent and comprehensive analysis of the agency and the tax rolls that would consider such disparate elements as technology and manpower.

And the Department of Assessments and Taxation ought to be leading the charge. The agency's credibility is at stake. If, as Mr. Young believes, assessors have done an admirable job with the resources available, then we can see no reason why an outside audit wouldn't be helpful.

When an assessment is judged too high, a property owner suffers unfairly. But when assessments are judged too low, other owners pay a similar price — bearing the burden of property taxes unequally. It helps keep tax rates high and breeds resentment. Owners need to have confidence that everyone is getting fair — and equal — treatment from state assessors.