The latest DWI arrest of a Buffalo man who already has seven convictions for driving while intoxicated is a frightening example of how justice is, or is not, meted out.

Alexander F. Snow, 32, of Seneca Street, was involved in a hit-and-run incident earlier this month that injured a city motorist and contributed to a second hit-and-run involving a parked police car, according to police. The injured city motorist fortunately suffered just minor injuries.

Snow has only been charged with this latest offense. But the question is how he got the opportunity to be arrested again and how many others are out there driving while intoxicated despite previous convictions.

Snow has a history of DWI convictions and sentences that is almost beyond belief. On his third conviction, this one a felony level in 2007 in Lackawanna, he pleaded guilty and was sentenced to the maximum, which is 1-1/3 to four years. Yet on his fourth DWI the following year in the city of Buffalo, he pleaded guilty as charged to his second felony and got only eight months. In 2010, he was pulled over on Grand Island. Snow eventually pleaded guilty as charged to a more serious D felony, and yet the judge put him on probation.

At some point, Snow’s license was revoked. But that didn’t stop him from taking his mother’s SUV and hitting several other vehicles. The arresting officers say he admitted to being intoxicated.

The sequence of penalties is mystifying. One would think that as the felonies multiplied, he would be sentenced to more time in jail to persuade him to get the help he needs to break his cycle of drinking and driving. But the justice system somehow does not always work that way.

This situation says more about the judges than the defendant. In cases where someone has broken the same law over and over again, how does he manage to get lesser and lesser punishments? Obviously those sentences are not deterring the behavior, and the results are staggering.

Driving while intoxicated is the No. 1 crime prosecuted by the Erie County District Attorney’s Office at both the felony and misdemeanor levels. DWI is more than 20 percent of the office’s felony caseload. Seven attorneys work solely on felony DWI cases. To his credit, the DA does not plea bargain felonies down.

Most of those felony cases involved repeat offenders. Obviously, those drivers are not getting the message that drinking and driving is a lethal combination.

The fact that the most common crime prosecuted in Erie County is felony DWI, and most of them are repeat offenders, is disturbing. Decreasing the punishment as convictions pile up is even more disturbing. Judges need to protect the public from the menace of DWI.