• A domestic investigation is a general term describing investigations involving individuals and companies. Domestic investigations may also involve matters of infidelity, child custody, child abuse, child neglect, elder abuse and neglect, and animal abuse and neglect. A domestic investigation may involve the activity of persons in a pre-engagement or common-law relationship. ┬áIt is always a good idea to know about the individual before you get involved with them either in a personal or business relationship.