Details to be resolved along the way, as the wall/fence/barrier, call it what you must, so long as it, by itself, is an effective STOP to passage for everyone who tries such illegal entry. Why is this so difficult to understand?
Catching trespassers is not the goal, not the primary goal. Trespass costs us all, way more than I think it should, and laws need to be updated, which means politicians need to be thrown out of office, so new legislators, not the ones who are beholden to anti-American interests through current bribery, campaign fund scams and whatever interests continue to allow thwarted effective STOPPING of vehicle and foot traffic across our legal borders.
Meanwhile, a WALL, high enough and strong enough, and continuous enough to be fully effective in stopping all unauthorized entry, must be the goal and must be the fact.
When all entry on foot or vehicle is forced to be at legal ports of entry, the Wall will have become effective, and ever increasing technology will continue to help prevent illegal cargo, including human cargo, from harming US Citizens.
Where for whatever reason a physical barrier cannot be effective, then whatever means may be employed to accomplish the job must be effected.
The more passive the better, so it works all the time, day and night, attended and not attended at any given point or moment. Beyond that, additional steps to prevent criminal entry are welcomed, and totally effective means to capture or otherwise neutralize those who would attempt criminal entry are welcomed.