What are contact stains?

Contact stains refer specifically to blood stains that occur when an object comes into direct contact with a blood source. This typically means that the blood is transferred directly from the source (such as a wound) onto another surface, creating a distinct impression or mark.

Answering with bloody footprints left at a crime scene accurately captures this concept as it describes a situation where a person's foot makes contact with blood on the surface, transferring that blood and creating a stain that indicates movement and possibly the path taken by an individual.

Although stains created by blood splattering, those resulting from wiping blood, and blood patterns indicating a struggle involve blood as well, they do not fit the definition of contact stains. Splatter stains arise from blood droplets being projected due to force, wiped stains are the result of cleaning or brushing against blood, and struggle patterns indicate physical confrontations. Thus, the option relating to contact stains specifically highlights the transfer from one source to another without the intervening actions that characterize the other types of blood stains.