From the announcement:
You start out with a hiding screen, one Magnifying Glass token, a pencil, and your trusty Casebook to record your findings.
All the elements of the crimes are represented with cards in three different decks, consisting of Persons, Locations, and Weapons in ten different colors (some of the colors are removed for groups of less than six players). Locations are either Indoor or Outdoor, People are either Male or Female, and Weapons are either Up Close or Ranged. These are important details to know when trying to solve a case.
Everyone is dealt one card from each deck and then two random cards, with the leftovers forming the face down Secret Informant cards in the center of the table. From your hand, you select the elements of the crime for the person to your left while the player to the right selects the elements of your crime. This leaves you with two extra cards hidden behind your screen.
You’re given one card from each deck (Person, Location, and Weapon), but instead of looking at the cards, they’re placed in their hiding screens facing away from you towards the center of the table. All the other detectives can see the details of your case except for you. In turn, you’ll be able to see the details of the cases your rival detectives are trying to solve.