Groups use a form to apply to investigate a site. This form is perhaps the most commonly used instrument for gaining access to a site and protecting the group from future liability. Even solitary investigators or small groups should use a form. There is no way to legally conduct an investigation without it, and those who do so are setting themselves up for a lot of trouble.

Without this basic form, investigators can be arrested and charged with trespassing or perhaps breaking and entering. Neither does much for the perpetrator's reputation.

To ensure that this form is legally binding, have an attorney draw it up or purchase one from a website that guarantees the form's viability. This is a little like buying insurance. If the client later alleges that the group did not have permission to enter the premises or did damage to it, having the contract and dated photos of the site can save you from a lawsuit, or worse.