The Post's report on the Department of Justice's findings concerning the Montgomery County Police [front page, Dec. 3] said that the Montgomery County Police wrote 21 percent of their traffic tickets to black motorists while the county's black population was 12 percent. The story didn't explain the methodology used to reach these percentages or whether Justice Department investigators simply looked at raw traffic ticket numbers. That would have been a great disservice to the citizens of Montgomery County. Here is why.

* Socioeconomics, not race, is the main reason for nonmoving violations. Unfortunately, minority groups are more often than not in a lower-income group and more likely to generate these types of tickets.

* Concerning moving violations, areas with higher numbers of black immigrants, who are both new drivers and may not have a history of watching parents and friends drive during their formative years, usually produce poorer drivers. Far more recent immigrants are from Africa and Latin America in Montgomery County than from traditional white population regions--of Eastern Europe for example.

* Both by design and officer request, police departments often have more aggressive officers assigned to the busiest areas. This often puts officers who are more likely to write tickets and make arrests in areas that have higher levels of minority populations.

I'm not saying there are not problems in the Montgomery County Police Department. But this traffic ticket example of minority profiling is badly flawed.

JOHN HOFFMANN

Olney

The writer is the Washington correspondent of Law and Order, a police management magazine.