A note on Trust
When asking you to check it, the owner of the device is trusting you with likely the most intimate possession they have. Be mindful of that.
For example, when checking phones it might be inevitable to have to go through SMS and WhatsApp messages to find potential malicious ones. When checking through computers, you might come across documents and personal pictures. In some cases, going through such data stored on their devices might resurrect traumatic experiences. Be mindful of that too.
In some cases you might need the owner of the device to enter their password, such as for example when checking Mac computers, or entering the PIN code to unlock their phone. Obviously, avoid watching over as passwords are being entered.
Make sure you comfort the owner, explain them exactly what you are going to do, ask for their consent, and offer to interrupt at any time.