Receiving a visa authorization is not automatic in the United States even for those who are qualified in high-need employment fields. The USCIS has significant latitude to deny visa authorization under certain circumstances. The nature of the criminal act matters in all final visa decisions when a criminal record exists. However, sometimes visa applicants with marginal criminal issues can still be approved with acceptable American citizen sponsorship, such as a farmer who wants a particular applicant to work for them. But those with serious criminal histories will have difficulties.
Drug crime record
The first unacceptable criminal activity is drug use, possession, and especially trafficking. Criminal charges for drug activity also often accompany other crimes that are considered violent, such as using a handgun while in its commission. Even one conviction can matter regardless of the amount of time that has lapsed since the occurrence, meaning general employment visas can be difficult to attain for those convicted of drug crimes.
Fraud
Fraud is another issue that the USCIS is also concerned about, as individuals can gain entry into the country and commit the same types of criminal activity. Fraud can actually be perpetrated in silence with only a paper or digital trail to determine what has happened, which means that detection can be difficult if the same pattern of behavior were to continue. Fraud typically is associated with theft, and theft is a serious legal matter in America. General employment visas can be easily denied for fraudulent activity.
While a criminal record can indeed be justification for a visa denial, having a reputable sponsor and solid legal representation can sometimes result in a visa approval. There are immigrants who reside in the U.S. illegally, but they face deportation at any time when they have any type of legal confrontation. It is always best to enter legally when possible.