At and about "Our Lawless Mexican Border." The link is an indirect link to the WSJ column that appears in Saturday's WSJ and written by Leo W. Banks. Without a WSJ on-line subscription, you won't be able to read the entire article, but you will get the gist of it. However, if you let me know, I will email you a full copy of the column.
Another approach is to go the Tucson Weekly and read Banks' other articles on the subject. Here's a good one to start with.