There has been much chatter about the need for tighter immigration security. Tashfeen Malik is the Pakistani woman who entered the U.S. on a K1 fiancee visa and was involved in San Bernardino massacre on December 2. Some advocates push to terminate the K1 visa program.

K1 fiancee visa applicants are treated as immigrants for purposes of immigration processing. All immigrants, including those applying for a K1 visa, have a thorough security check. By comparison, non-immigrants such as visitors to the U.S., have much less screening. For immigrants, the Department of Homeland Security and overseas consulates engage in a multi-agency security screening that involves the FBI, Interpol, and foreign governments. Police records from the locations where foreigners have traveled are checked.

A misnomer is that the DHS only checks what is put on immigration forms. This is not true. An independent background check is undertaken. While it is true that certain forms ask whether the foreigner has ever been arrested or convicted of a crime, the answers to those questions are not reliable. They are not relied upon when conducting security checks.

The purpose of many questions on forms is to detect whether a foreigner is telling the truth, but the DHS and consulates do not rely on such information. If the foreigner indicates he or she has no criminal arrests and the agencies discover an arrest, the foreigner is permanently barred from the U.S. for lying to an immigration officer.

Apart from security checks, the U.S. government engages in data mining under the Patriot Act, as it’s been updated since the 9-11 attacks. If the foreigner is engaged in chatter with known terrorist suspects, the results of that data collection can become useful to the U.S. government when considering immigration requests.

I’ve worked with the U.S. consulate in Islamabad for many years. I find the consulate staff to be very difficult and reticent about issuing K1 visas or any other immigrant visas. Sometimes, they can be unreasonable in denying visas without good cause. I do not know whether Ms. Malik processed her case through Islamabad or Riyad. However, it is normal for a U.S. consulate in a third party country, such as the one in Riyad, Saudi Arabia, to liaison with the foreign national’s home country (Pakistan) to determine whether there is a security or other concern. It would generally be as difficult or more difficult for Ms. Malik to hide something by processing through Riyad since she was not a Saudi citizen. The U.S. consulate in Riyad would naturally be circumspect about taking her case when normally Pakistanis would process through the U.S. consulate in Islamabad.

My suspicion is that the security checks in this case were proper, but that Ms. Malik had no criminal convictions or other red flags that would draw attention to her. Not everyone who is radicalized has notable characteristics. It just sometimes happens that people will lay low and then commit a criminal act. This is a common problem with school shootings in the U.S. There are not enough warning signs to draw attention to a problem. This is not a failure of government, but a part of human nature and criminal activity. Things happen on a rare occasion, but we should no more shut down global migration than we should shut down schools. Both activities – attending school and traveling cross-border – are part of membership in society and both activities carry some risks.