Metal detectors missing contraband?

[BugPowderDust]

Are metal detectors 100% effective? The reason I ask is that a prisoner smuggled a drill through a metal detector from the workshop, to his cell. I only found it from a cell block search.

So, are they supposed to be fallible, or is this is a bug?

Screenshot: http://i.imgur.com/qTCOILS.jpg

EDIT- just to make it clear to latecomers to the thread- this has been answered below- thanks

[Kolchak]

Hmm, the change list for Alpha 12 only mentions false positives not false negatives. However the picture shows only one guard in the vicinity (and he mightn't be close enough to operate the workshop detector), is it likely that there were guards present when the prisoner walked through the detectors?

As a note to other posters: I'm quite interested in what happens if there are no guards present - would the metal detector go off but not apply the auto-search (allowing me to manually search) or would it simply pass by unnoticed? Thanks

[BugPowderDust]

My understanding was that the detectors don't need to be operated, they just work? They seem to flag the prisoner with a magnifying glass icon, and a guard picks up the job whether they're near or far....or maybe I'm missing something

[BugPowderDust]

Same prison, different metal detector:



Can they go to the 'side' of the detectors?

[RGeezy911]

Here's what happens,

When a large group of prisoners move through metal detectors, there is a very high chance they will flag an inmate for a search. However, once a metal detector goes red, it will stay inactive for 3 seconds and then resume as normal. During this brief period, it is very possible for a prisoner to slip through the metal detector unnoticed. This is very commonly seen in heavily populated areas of prisoners that travel through one hall / corridor regularly.

You are also correct in that metal detectors will give out false positives, and this will also render the detector inactive for 3 seconds after a flag. This is to indicate that metal detectors are not 100% reliable, and the same can be said for guard dogs.

Refer to: http://devwiki.introversion.co.uk/pa/in ... l_Detector

Hope this helps!

[BugPowderDust]

Ah, many thanks- that is very helpful Setting up double (spaced) metal detectors along a choke point may not be a bad idea.

Thanks for the answer

[Kolchak]

My understanding was that the detectors don't need to be operated, they just work? They seem to flag the prisoner with a magnifying glass icon, and a guard picks up the job whether they're near or far....or maybe I'm missing something

Certainly when they were first introduced a guard needed to be nearby. The guard who does the search could be anywhere (since the AI just registers it as a job), but my understanding is that without a guard somewhere nearby the job wouldn't be created

[Foxsake]

If the prisoner was searched after he managed to return to his cell and hide the drill, it wouldn't have been found on him so would've been thought of as a false positive.

[BugPowderDust]

If the prisoner was searched after he managed to return to his cell and hide the drill, it wouldn't have been found on him so would've been thought of as a false positive.

Interesting point, thanks for mentioning it...i'll have to bear that in mind and order a cell search also

[UberFuber]

Here's what happens,

When a large group of prisoners move through metal detectors, there is a very high chance they will flag an inmate for a search. However, once a metal detector goes red, it will stay inactive for 3 seconds and then resume as normal. During this brief period, it is very possible for a prisoner to slip through the metal detector unnoticed. This is very commonly seen in heavily populated areas of prisoners that travel through one hall / corridor regularly.

You are also correct in that metal detectors will give out false positives, and this will also render the detector inactive for 3 seconds after a flag. This is to indicate that metal detectors are not 100% reliable, and the same can be said for guard dogs.

Refer to: http://devwiki.introversion.co.uk/pa/in ... l_Detector

Hope this helps!

I'm not sure if detector gives out false positives as I've noticed that guard search do turn up with false negatives. I've noticed, in contraband screen during a cell-block search (just cell-block, not inmates), that there's quite a few contraband where they're "Detected" by the metal detector, but wasn't found at all until it was "Hidden". So it could be that both metal detector and guard can result in false negatives.

[m_wellbring]

The detectors do give false positives.

Metal Detectors automatically trigger a search of a prisoner when they detect something
Metal Detectors now fall out of action for 3 seconds after detecting something
They also incorrectly detect something a small percentage of the time, resulting in unnecesary searches

[gmyx]

Is there more than one path? I see the path to the left has no metal detector. Prisoners will take the longer route to avoid metal detectors when they need too avoid getting caught.

[dogsbody]

I'd have to re-watch all them all, but I'm sure it's been mentioned in an Alpha video that they will not give an indication 100% of the time, reflecting prisoners skill/determination to slip something past, although it was mentioned that if there are detectors/dogs between the theft location and their objective destination then that will decrease the chance of prisoners trying to smuggle stuff through. This is particular.y noticeable with min sec prisoners. I.e. Prisoner Smith wants a spoon to dig a tunnel but as there are 3 metal detectors between him and his cell, he decides it's not worth getting caught, but Max Sec Prisoner Bob REALLY wants that spoon so will stop at nothing to get it there

[nini]

I've got doubled metal detectors covering most large prison doors linking to other areas and seem to always have a good few prisoners smuggling out knives and forks every time they goto the canteen. I've also found it's real important for workshops as there's a similar level of weapon smuggling like hacksaws, drills and hammers.

False positives though are fairly common.

[_alphaBeta_]

Recommend you read the entire Alpha-12 announcement and watch the video. I also started a thread way back on the changes to the metal detectors.

In any event, the detector looks like it's missing contraband because it "falls out of action" for 3 seconds after going off. While I don't think the prisoners are specifically coded to exploit that system, what you're seeing are prisoners that are setting off the detector and other prisoners carrying contraband passing safely through the detector when it's "out of action." Part of the issue is that prisoners tend to pass through players' choke points with detectors as a huge group. Would be neat if prisoners teamed up with a decoy setting off the detector so a buddy can smuggle something really sinister through.

In the thread I started, I suggested a turnstile or other guard outpost (others' suggestion) that essentially stops the flow of prisoners when a detection is made. Obviously this would also cause major traffic issues, which is a good consequence of using this system, and a reason why you may not want to use it everywhere. If you're flying and the person ahead of you sets off an airport security detection device, they don't have anyone else come through until the detector is ready again. As the thread discusses, however, being this is a game there has to be someway for contraband to make it into the hands of prisoners. Fool-proof metal detectors would be hard to defeat.