He's also had a recent mugshot taken which will help identify him with more the recent data held against him.

Did they take his index fingerprints? If not, he might have been lucky that they have not implemented that yet.

Going forward changing the name would not help if they have computerized and have accessible the criminal fingerprint file (assuming there is one). Does Thailand have a national fingerprint database (i.e. Royal Thai Police) ??

Edited April 25, 201610 yr by bkkcanuck8

The OP friend should sign up for the Premium Thailand Elite Card service which cost two million Baht if I remember correctly.

Its a lot of money as the funds are shared between different departments and I would not say anything to the TE service.

After a few days they will respond to the OP's friend my email and if they get a conformation from the Immigration he is clear to apply and pay for the visa.

This is the best possible legal way to let him into the country at a high price.

friend of mine had a conviction in Thailand for a bit of ganja back in the eighties

To get blacklisted I am sure that it was a lot more than a "bit of ganja"

And considering that one of the most popular forms of Marijuana at the time was known as "Thai Sticks" my bet is he was dealing or at a minimum trying to set up a score

Back in the 1980s, possession of any quantity of ganja by a foreigner here was a very serious matter. The UK travel advisory still has this

Penalties for possession, distribution or manufacture of drugs are severe and can include the death penalty.

Possession for personal use is not as serious as previously, but back in the 1980s, he was lucky to avoid a lengthy prison sentence.