I was reading Destructoid's interview with the developers of Payday: The Heist where they go through the arsenal of weapons. One of the devs had this to say regarding the trip mine weapon:
Insider hint: Put a trip mine on the ground, switch off the laser beam (yeah you can switch it on and off as you please) and then when some enemy who can take a LOT of damage (cough Bulldozer cough) stands near it, shoot at the trip mine (preferably with a weapon that has some spread, so that you know you'll hit it) and BAM! That sucker is GONE!
This seemed to imply to me that if you turn off the laser beam, the AI may be less likely to notice and/or react to the trip mine. Is this actually the case? Or does turning off the laser sight just make it so the trip mine must be manually detonated, allowing you to be more precise about its explosion?
I don't have trip mines yet, so I cannot test this myself.
Best Answer
The AI isn't particularly clever regarding trip mines anyway. With or without the detection beam, enemies will run through it. But the advice given in the interview works pretty well: put trip mines on the floor, turn off the detection beams and simply wait to have several enemis around it before you shoot it. There are even challenges/achievements for this ("Three guys went on a trip", etc).
However, some players think that trip mines can modify the path that police take to get to you:
Source: http://payday.wikia.com/wiki/Trip_Mine
But I sincerely doubt it. Maybe it only works in some simple or obvious cases. What I know: if you plant mines everywhere in Panic Room stairwells, police will use it anyway and trigger the mines...