Subscriber Discussion

On/Off Switch For Video And Audio In An Interrogation Room


We have a customer requesting an on/off switch in a PD room for interrogration purpose. They have Genetec VMS and we can propose appropriate camera (most likely Axis with I/O). Any solutions that exist out there. any feedback on this integration would be very helpful.



Hello Nirmal:

To clarify, your customer wants a physical "on/off" switch located in the room they can toggle during interviews?

Hi Brian - yes thats correct. In the past, we used Axis encoder to incorporate customer's existing analog camera. We simply mounted miniature SPST switches in a Bud box with labels, ran them to the I/O of the axis encoders and configured the I/O as switch inputs. This was done using OnSSi.

i was wondering if there is anything else we need to consider esp. we go with Axis IP camera and Genetec solution.

Good news: the exact solution you used in the past would work with a mic-enabled IP camera (with I/O ports) and Genetec.

You could have the switch input disable the mic on the camera or preempt recording in Genetec via a rule, depending on the recording device source (internal mic/external mic).

If using an external mic, you could also install your switch to just kill power to the preamp or head unit.

What we have done in the past is much more low tech, but gives the PD more piece of mind; just have a switched outlet installed in the ceiling above the interrogation room, and a switch on the wall. Power the Axis IO unit off of that outlet. Let the PD know that once they turn the switch on for recording, they need to wait 3 minutes for the Axis unit to boot up and connect to the server.

Well, it may not be much to look at, but it'll get the job done!

Thanks for sharing!

Does cold-cycling the power on an IP camera introduce any long term reliability issues? My instincts tell me "how could it not introduce long term reliability issues?" but I'm interested in actual results.

Honestly I didnt read that it was an Axis camera with IO, I was thinking the P8221... I dont think I would use that setup off of an actual camera.

How about a small standalone slowly blinking red-bulb with push button toggle, with area constrained motion detection. Simple to use: If the light is on, then its recording!

@SeanPatton, why 'more piece of mind'? I'm not knocking the switch, but I think of power-cycling equipment like take-off and landing of an airplane, that's where the equipment is most likely to fail. Personally I've witnessed several Axis cameras that were fine once booted, but occasionally would have to be cycled twice. What's your experience been?

Also on a lighter note, doesn't the 3 minute cycle delay preclude or at least make awkward the use of the time honored cinematic tradition of turning off the recorder momentarily to make some private and constitutionally inappropriate suggestions to the Mirandized detainee, before resuming recording?

Question: couldn't you just wire a SPDT button into the I/O port of a camera and program it to only record when the I/O is closed? Does any camera have this ability?

Even better, you can write a rule in Axis' interface that only affects audio function:

In other words, do everything you describe, but configure the button to only affect audio recording by turning power on/off to the mic only. Leave the camera to always record video or on motion, etc, regardless of the on/off button.

Lip readers be damned! ;)

Does any camera have this ability?

Do you mean independent of the VMS, as in contact closed send stream, contact open stop stream? Or edge recording?

Most VMSes I've used let you create an event based on I/O just like it as motion detection generated one... for supported cameras only, of course...

This would not be a function of the camera but of the VMS the camera is connected to. I don't know Genetec very well but I would have to assume that an advanced VMS would have this basic functionality: "record on event" where "event=camera input open".

Then wire in a toggle switch into the input of the camera. Toggle on= record; toggle off=stop recording.

I would think that most VMS would do this without any issue at all. This would be much better than cycling the power on the camera.

Yup. That's what we did before for the exact scenario.

Most police interrogation rooms prefer that the cameras be covert, enclosed in a housing that resembles a smoke detector, PIR sensor, clock, etc. The perps usually clam up when they see anything even closely resembling a camera in the room. Unfortunatelythere aren't many manufacturers of IP covert cams (unless you want to rig something using an Axis P12but that doesn't have an audio input) These are usually analog cameras (Kalatel used to make all kinds of them) and require a separate audio setup such as the Louroe Verifiact A microphone mounted on the ceiling and IF-1 module. Connect all of these to an encoder with audio and I/O functions (such as Axis or Verint) along with a wall or under-desk mounted toggle switch connected to the input to trigger recording as you would do with any alarm based schedule, map the I/O point to start and stop recording.

Your covert experience is exactly opposite what every police department in my area requested. They wanted multiple cameras, and preferred box cameras. One captain wanted 5MP cameras staring the interviewee in the face in his interview rooms so he could see beads of sweat.

Wow... Maybe it's a regional thing here in the South. The half dozen or so police/sheriff offices I have worked with don't want anything that even resembles a camera in the interview rooms.

For one project, we custom fabricated corner mounts for the Kalatel PIR covert analog cameras and they could see the entire room. The Verifact A mic worked great, put required a little testing and tweaking, the PD wanted it to pick up the slightest whisper or mumble, ceiling mounted it sort of resembles a smoke detector.

When they mean "anything you say can be used against you", they mean anything. An officer doesn't even have to be in the room. Many times the interviewee would start talking to themselves or break down crying once the detective left the room. Yup, they can use that.

Not sure if beads of sweat are admissable...

Or maybe every department has its own procedures?

I've sold interview systems to departments that wanted fully covert video, non covert but "low profile" video, vandal resistant cameras, non vandal resistant cameras, make the camera as big and obvious as possible...

One captain wanted 5MP cameras staring the interviewee in the face in his interview rooms so he could see beads of sweat.

Was that overt shot requested just so one could actually see the beads, or to actually cause the beads as well?

If the former then maybe its not quite as 'at odds', since the overtness is just a unavoidable side-effect of the required pixels on target.

If the latter, meaning they actually were requesting overtness, then agreed this is altogether different. In that case maybe a nice upgrade to the system might be a footswitch operated, flush mounted, Raytec 940nm Interrogator Illuminator to supplement the standard issue swing-mount 120W incadescent bare bulb w/pull chain visible illumination they would already typically have.

I agree with the comments about covert vs. overt it is a localized decision (IMO).

We typically suggested a switch sometimes in the room sometimes just outside again local preference drives that. A key we always felt was positive feedback at the switch i.e. an indicator LED or lamp driven by the change in state at the recorder. In one large install in Illinois part of the requirement was confirmation that the recording was off in case of a visit by an attorney in the interview room monitoring was still possible for saftey reasons. It did seem to me that more and more departments did not seek covert, the assumption being hey we have cameras all over the place so why hide them and many suitable cameras with wide FOV's today are available in small compat form factors that are almost invisible in the first place. We have also recently deplyed a PD with Genetec VMS and we set up rules that defined an event. The switch contact and lamp on/off used teh digitaial In / Out points on the Axis cameras we installed Laroe verifact mic elements along with the appropriate IF series pre amps we landed the analog audio at the camera as well we felt the Laroe gave us better sound quality than the built in camera mic options. IMHO audio is what trips up a good interview system and more than one investigator informed me audio was more imprtant than the video having both is great but audio is the priority.

From a California / West Coast perspective most Law Enforcement agencies and the detectives who use the interview room do NOT want a camera that is obvious. If the Officer wants to go with a low key approach then it's set up for that and if you want to add some stress to the process, there are much better ways to do that than to have a camera stuck in a corner. If you poke around a bit you will find that the FBI does not as standard practice use audio or video during most interviews.

John Grocke's recommendations are spot on for what I have seen/used in police interview rooms and agree that it still pretty hard to find a covert IP based camera.


We just switch power on our LouRoe microphones and analog cameras. One caveat to that approach: the encoder used must be capable of handling loss of camera signals with aplomb. I've found that many encoders do funny things when camera power is switched off and on. It also depends on the camera itself.

I've seen encoders choke in these situations, with symptoms including continual dropped frames, resetting their programming and even exhibiting strange video artifacts and huge bit rate increases; all requiring a reboot to fix.

On the other hand, other encoders exhibit no problems.

Thanks everyone! Great information and even Genetec provided a very detailed solution.