UK: What information are the police legally required to collect when going door-to-door, and why?
<p>A few days ago, a police officer knocked on my door in the evening and asked whether I had noticed any disturbances in my street earlier in the day - he said it was in relation to reports that they'd had, and were investigating.</p>
<p>I informed him that I hadn't noticed anything, and he then asked whether I had been at home at the time of the disturbance, and what I was doing at that time, as well as taking my name and date of birth.</p>
<p>What are the reasons/ legal requirements that the police might need my personal information, given that I had not been able to provide any further information/ witness testimony to the incident that they were investigating?</p>
<p>I would understand the need to collect it had I been able to provide any further information regarding the incident, or been asked to provide a witness statement, but given I hadn't been able to, what would the legal reasons be for them to collect/ hold this information?</p>

<p><strong>What are the reasons/ legal requirements that the police might need my personal information, given that I had not been able to provide any further information/ witness testimony to the incident that they were investigating?</strong></p>
<p>The police in <a href="/questions/tagged/england-and-wales" class="post-tag" title="show questions tagged &#39;england-and-wales&#39;" rel="tag">england-and-wales</a> have a duty to undertake reasonable lines of enquiry and to carry out a proportionate investigation in to allegations of crime.</p>
<p>No-one is legally obliged to answer <a href="https://www.app.college.police.uk/app-content/investigations/investigative-strategies/house-to-house-enquiries/#providing-reassurance" rel="noreferrer">house to house</a> questions but, notwithstanding the honesty and integrity of the majority of members of the public, any information held by the police may need to be corroborated to identify or eliminate suspects, witnesses, evidential opportunities or other lines of enquiry.</p>
<p>Also, if it is established that someone has no information that may assist the investigation this is recorded to prevent duplication of effort thus enabling the police to focus their resources accordingly.</p>
<p>All the while complying with the relevant privacy and data retention legislation.</p>

united-kingdom privacy police data-protection personal-information