Gasoline residues present in fire debris serves as important evidence in arson investigation. In view of safety considerations, fire investigators do not enter fire scene immediately after fire extinguishing activity. In this perspective, gasoline residue in burnt carpet was analysed in relation to time elapsed after a fire to evaluate the influence of evaporative weathering process on the detection of gasoline traces from fire debris. Simulating fire condition, carpet samples poured with gasoline were burned, and the fire was extinguished with water before exposure to varying evaporation time at room temperature. All burnt carpet samples were then extracted by hexane and analysed using gas chromatography-flame ionisation detector. Selected peaks were then subjected to principal component analysis (PCA) for clustering. Experimental results revealed rapid evaporation of gasoline during the first 30 minutes, followed by continuous but non-linear decrease up to one-month interval. Four clusters were found in the PCA plots wherein samples that were subjected to less than nine hours exposure were located close to positive control and could be distinguished from the rest. Hence, it is recommended that safety measures should be completed within nine hours.