If your neighbor was arrested, charged and convicted of a DUI, I am sure those in his neighborhood already know about it or, if far in the past, could care less about it.
Getting a background check done on your previous employer can be dangerous if you plan to obtain the information through, say, an online background check company. Erroneous information can appear on these reports (ie. a DUI conviction belonging to a person of the same name).
Background check companies often compile data using names, and names can be shared by several different people. These companies advise all recipients of a background check report that errors may appear. The background check company leaves it to the recipients of the reports to verify all information appearing.
You can obtain more accurate information on an individual by doing a public records search on your own, accessing criminal records and incarcerations and court records and arrest records right at their source, then cross-checking names and addresses and birth dates to verify.
It would be your responsibility to make sure that an arrest on a DUI was actually charged as a DUI, or that charges were not dismissed, or that the conviction was not on a lesser offense, or that the DUI did not belong to a person with the same name, or that the DUI was not erroneously entered by the court clerk under the employer's name.
If ANY inaccurate criminal history information is distributed to others, that opens you up to an expensive defamation suit which you would almost certainly lose.
If all of the information you gather on your former employer is verified as accurate, and you go ahead with your plan to distribute this information to his neighbors, that may eliminate any risk of a defamation suit but there are other legal actions besides defamation that this employer could take against you (harassment, for one). Hot Topic mentioned a restraining order being issued against you, and that is a real possibility - you would be looked at as a disgruntled ex-employee and a threat to the employer and his family.
As everyone has already said, your idea is a stupid, childish, immature and potentially legally dangerous idea. Don't do it.
