“Touch DNA” can often show if a person handled a particular item at a scene of crime. Touch DNA occurs when a person deposits particles of DNA from their skin onto an object that they have touched. However, there can also be traces of DNA when a person never touched an object. This occurs when a person comes into contact with someone, usually for a more extended period of time, and picks up their DNA particles and thereby transfers the DNA to another place or object. Researchers found this kind of “transfer DNA” after they had subjects shake hands for two minutes. While two minutes is unrealistic for a simple handshake, such extended physical contact can occur in intimate relationships for instance.