3. Results

3.1 Long-Term Experiment

In the long-term experiments, the bloodstain scans showed little variation between 1.5 hours and four weeks (Figure 1A). For the long-term experiments, kurtosis values showed slight variation over the four weeks (Supplemental S3), although the values were always less than three, indicating platykurtic distributions, or height profiles with multiple heights of similar frequencies. Skewness values showed similar timewise fluctuations but were influenced by individual bloodstain variation. For example, bloodstain 1 had overall negative skewness values, while bloodstains 2 and 3 had positive skewness values. Surface roughness slightly increased within the first day, but then plateaued over the tested timeframe. Maximum height was measured from the horizontal and vertical slices taken from the long-term bloodstains, where minimal change was observed in the height profile over time, except for the earlier time points (1.5 and 6 hours) which had lower heights at the centre of the bloodstain.