The second step is determined by the type of possible demonic activity. If it is regarding a house, then the priest you first contacted will likely come out and bless the house. If the problem is with an individual, then a psychological examination may be performed before going further.
The USCCB explains the reasoning behind this step of the process, “It is advisable that every diocese establish a protocol to respond to inquiries made by the faithful who claim to be demonically afflicted. As part of the protocol, an assessment should occur to determine the true state of the person. Only after a thorough examination including medical, psychological, and psychiatric testing might the person be referred to the exorcist for a final determination regarding demonic possession. To be clear, the actual determination of whether a member of the faithful is genuinely possessed by the devil is made by the Church, even if individuals claim to be possessed through their own self-diagnosis or psychosis.”
Determining the source of the problem is always a balancing act, “The exorcist is instructed to employ the ‘utmost circumspection and prudence’ before proceeding to the rite. Throughout his ministry, an exorcist must establish a balance within his own mind between not believing too easily that the devil is responsible for what is manifesting, and attributing all possible manifestations solely to a natural, organic source.”