"Before 2010, federal data show the border city was mired in violent crime and drug smuggling, thanks in large part to illicit activities spilling over from the Mexican side. Once the fence went up, however, things changed almost overnight. El Paso since then has consistently topped rankings for cities of 500,000 residents or more with low crime rates, based on FBI-collected statistics. The turnaround even caught the attention of former Homeland Security Secretary Janet Napolitano and other Obama administration officials, who touted it as one of the nation’s safest cities while citing the beefed-up border security there.
Federal data illustrates just how remarkable the turnaround in crime has been since the fence was built. According to FBI tables, property crimes in El Paso have plunged more than 37 percent to 12,357 from their pre-fence peak of 19,702 a year, while violent crimes have dropped more than 6 percent to 2,682 from a peak of 2,861 a year."
https://nypost.com/2018/01/13/we-already-have-a-border-wall-and-it-works/
So then, does this mean you doubt effective security barriers have anything to do with the cause and correlation of reduced crimes against persons or property in most places where there are effective security barriers to thwart illegal trespassing?