FORENESICS DNA and BOTANY Forensic Botany is the analysis of plant material in both civil and criminal law enforcement. Plant evidence can be used to destroy an alibi, help determine time since death, put a suspect at a crime scene, or tell where someone or something has been. The basis of forensic science is The Exchange Principle, now called Contact Traces. Very often, trace botanical evidence can link an object or suspect to the scene of a crime, as well as rule out a suspect or support an alibi. A plant''s anatomy and its ecological requirements are in some cases species-specific; correct interpretation of botanical evidence can give vital information about a crime scene or the whereabouts of a suspect or victim.