7. Using the equipment

It is important that a CCTV system produces images that are of a suitable quality for the purpose for which the system was installed. If identification is necessary, then poor quality images which do not help to identify individuals may undermine the purpose for installing the system.

• Do the recorded pictures and prints as well as the live screens produce good clear pictures? This is important to ensure that there has not been an unacceptable loss of detail during the recording process.
• Have you considered the compression settings for recording material? In a digital system, a high level of compression will result in poorer picture quality on playback.
• Have you set up the recording medium in such a way that images cannot be inadvertently corrupted?
• Is there a regular check that the date and time stamp recorded on the images is accurate?
• If automatic facial recognition technology is being used, are the cameras placed so that facial images are clearly captured? Are the results of any match checked by people before any action is taken?
• Has a regular maintenance regime been set up to ensure that the system continues to produce high quality images?
• If a wireless transmission system is used, are sufficient safeguards in place to protect it from being intercepted?

CCTV must not be used to record conversations between members of the public as this is highly intrusive and unlikely to be justified. You should choose a system without this facility if possible. If your system comes equipped with a sound recording facility then you should turn this off or disable it in some other way.

There are limited circumstances in which audio recording may be justified, subject to sufficient safeguards. These could include:

• Audio based alert systems (such as those triggered by changes in noise patterns such as sudden shouting). Conversations must not be recorded, and operators should not listen in.
• Two-way audio feeds from ‘help points’ covered by CCTV cameras, where these are activated by the person requiring assistance.
• Conversations between staff and particular individuals where a reliable record is needed of what was said, such as in the charging area of a police custody suite⁶.
• Where recording is triggered due to a specific threat, e.g. a ‘panic button’ in a taxi cab.

In the limited circumstances where audio recording is justified, signs must make it very clear that audio recording is being or may be carried out.

The use of audio to broadcast messages to those under surveillance should be restricted to messages directly related to the purpose for which the system was established.

• If there is an audio monitoring or recording capability has this been disabled?
• If an audio based alert system is being used are measures in place to prevent conversations being monitored or recorded?
• If there are audio communications with help points, are these initiated by those requiring assistance?
• If a message broadcast facility is used, are the messages limited to those consistent with the original purpose for establishing the system?

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6 Police use of body-worn video devices (headcams) is covered by the Home Office guidelines, "Guidance for the police use of body-worn video devices”, produced in consultation with the ICO. See the Home Office police publications page, http://police.homeoffice.gov.uk/news-and-publications/