Now in Phuket, taking fingerprints to conduct a criminal record check before issuing marriage certificate.
This because they think foreigners are just marrying for the Visa and possibility to stay longer.
They can only check for criminal records within Thailand, it is not possible to check for records in other countries.
But if you have company or children or been long time in Thailand the papers can be done in one day, if you are here short time as tourist it will take longer.