Contact with water and sediment can leave microscopic traces on clothing and footwear, including diatoms. These algae may help assess exposure to an aquatic environment, even when no trace is visible to the naked eye. An experimental study demonstrated the transfer of freshwater diatoms onto footwear materials, with differences in persistence and recovery between samples. These findings show that surface material, exposure conditions, and subsequent use are important when interpreting traces recovered from shoes. Research on clothing also demonstrated that diatoms could be recovered after extended periods following initial transfer. Their persistence varied with fabric type and seasonal conditions, indicating that some garments may retain useful environmental evidence over investigative timescales. In forensic applications, diatom assemblages recovered from clothing or footwear can be compared with reference samples from potential locations. However, similarity alone does not establish that a person was at a crime scene when an offence occurred. Previous exposure and alternative transfer routes must also be considered. The value of this evidence increases when samples are collected promptly, items are packaged separately, and their recovery and handling are documented to prevent the mixing of traces. In conclusion, algae on clothing and footwear may help test accounts and reconstruct aspects of movement and contact when their findings are assessed alongside other evidence.