Just as criminal forensics relies on advanced analytical tools and methods (e.g. fingerprint analysis, DNA, ballistics testing) to assist criminal investigations, environmental forensics uses advanced tools and methods to investigate and prosecute environmental crimes. The Environmental Forensics Team at the NSW Department of Planning, Industry and Environment has a wealth of experience working with environmental regulators, such as the NSW EPA, by providing expert scientific analysis and advice that can be used in prosecutions. Using a variety of advanced analytical methods including LC-MS/MS, GC-MS, FTIR, ICPAES and optical microscopy, unknown materials can be identified and linked back to potential sources. Key to successful environmental forensic investigations is the interpretation of analytical data. Understanding how chemicals move, change and interact with the environment is critical to data interpretation. The analytical methods and interpretations such as data for oil fingerprinting must be rigorous and defensible to be able to be used in legal proceedings. In this presentation, a range of case studies will be discussed (e.g. identification of unknown materials in stormwater drains, investigations into bird poisonings and oil spills), highlighting the breadth of environmental forensic analytical methods available.