U.S. immigration laws are quite strict, especially when it comes to granting benefits to people with crimes on record. This is true no matter what country that crime was committed in. Sometimes even a minor foreign criminal conviction leads to a denial of one's visa application, whether it was for a nonimmigrant (temporary) visa such as B-2 visitor, F-1 student, or H-1B worker; or an immigrant visa, leading to a green card.
Although being found ineligible for a U.S. visa due to a crime is a permanent problem (one that time won't erase), applying for a waiver can be a way to overcome this, as discussed in How to Obtain a U.S. Visa or Green Card When You Have a Criminal Record.
The two most common types of criminal visa ineligibilities are "crimes involving moral turpitude" and drug crimes, discussed below.
The first thing one might wonder is, how would a U.S. embassy or consulate find out about a crime committed outside the United States?
They typically obtain such information using a variety of sources and methods. In some countries, consular officers might have direct access to foreign criminal records. Each embassy also has U.S. personnel who liaise with local law enforcement to improve information sharing. Arrest records are published online in some countries or published in the daily newspaper.
Additionally, the U.S. visa application form asks several questions designed to ascertain an applicant's foreign criminal history. In some visa categories, applicants must provide a local police certificate.
Embassies and consulates are continually improving their access to foreign criminal records. Be aware that failing to disclose a prior arrest on a visa application could lead to a permanent visa ineligibility based on misrepresentation.
Crimes Involving Moral Turpitude (CIMTs) are said to involve "intent to defraud" or other "evil intent." Examples of CIMTs include not only the obvious (murder, aggravated assault, robbery), but various nonviolent crimes such as theft, crimes against the government, and crimes involving fraud.
It is sometimes easy to determine that a particular crime involves evil intent and is therefore a CIMT. For example, "assault with intent to kill" would clearly be a CIMT. In less obvious situations, the consular officer must review the local crime statute to see whether the conviction requires intentional action.
For example, the crime of "passing bad checks" might or might not be a CIMT, depending on the statutory language. If a conviction for passing bad checks in a particular country requires that the person intentionally wrote the check, knowing the check would bounce, then this would be a CIMT because the person would have to have acted with "intent to defraud" to be found guilty.
In other countries, one might be convicted of passing bad checks even without knowing the check would bounce, and thus passing bad checks would not be considered a CIMT by U.S. officials.
Crimes involving drug possession are not CIMTs, but drug trafficking crimes are. This is because U.S. immigration courts have determined that drug trafficking crimes have an element of "evil intent" that drug possession crimes do not.
If you committed a CIMT, you are in theory permanently ineligible for a U.S. visa. Nevertheless, you might still be eligible if you meet the "sentencing exception." This applies if you have been convicted of only one CIMT and the maximum sentence for that crime, in your country, is less than one year.
As you've seen from the above examples, charging and sentencing practices vary from country to country. For example, in some countries a person who steals cigarettes might be charged with misdemeanor shoplifting, which carries a maximum penalty of less than one year and would thus not result in a visa ineligibility even though it is theft crime and a CIMT. In another country, by contrast, a person who steals cigarettes might be charged with "theft," and the maximum penalty might be seven years. Even if this person receives no jail time, he or she would still be visa-ineligible, because the maximum penalty exceeds one year and the sentencing exception would thus not apply.
It can be difficult to determine whether certain offenses are CIMTs. Consult with a U.S. immigration attorney if you are unsure.
Even if a minor criminal conviction is not a CIMT, such as a "simple assault," it might still affect your ability to get a nonimmigrant visa. Consular officers have a fair amount of discretion in making visa decisions. If you have a recent conviction, even a minor one, the consular officer might not be convinced that you will abide by U.S. laws on your trip to the U.S., and might not return when you're supposed to.
All crimes involving drug possession, even small amounts of marijuana, create permanent visa ineligibility. Crimes involving drug trafficking might result in visa ineligibilities in multiple categories. Unlike CIMTs, there is no sentencing exception for drug crimes.
A DUI (driving while intoxicated or under the influence) conviction does not cause automatic visa ineligibility, but a consular officer might still deny your visa if it's recent.
If you have one DUI within the last three years or multiple DUIs within the last ten years, the consular officer must refer you for a medical exam with the embassy panel physician before issuing a visa.
Other offenses involving alcohol, like public intoxication, could also result in a visa denial or referral for a medical exam. Ultimately, if you have committed crimes involving alcohol abuse, the consular officer must be convinced that you will obey U.S. laws while traveling in the U.S. and that you are not a danger to yourself or others.