Man-made textile fibers are frequently encountered as trace evidence in criminal investigations. Examines the effects of burial in soil on the biodeterioration of synthetic textile fibers such as cellulose acetate, nylon, polyesters, and acrylics. Cellulose acetate fibers began to show signs of decomposition within two months after burial in common garden topsoil and were completely degraded within four to nine months. It was found that severely decomposed cellulose acetate fibers could be identified by pyrolysis-gas liquid chromatography even when other methods such as polarized light microscopy and dispersion staining failed. The solubility behavior of the cellulose acetate fibers also was altered. The other types of fibers showed no detectable alteration at the end of the 12-month study. -- AATA