Detection of targets in sonar data is heavily reliant on a sparse number of clues: signal-to- noise ratio, size, and shape. Statistical analysis of the resolution cell energy distribution is an additional clue that examines a target size area for mean value, standard deviation, skewness, and kurtosis. Derivation and significance of mean and standard deviation are well known. The other two measures of frequency distribution, skewness, a measure of symmetrical distribution, and kurtosis, a measure of peakedness, are less well understood. The four measures were calculated for target size windows in digitized, beamformed sonar data. Statistical values for known targets were computed over successive pings. The combinations of these statistical measures provide an additional clue to target presence versus background. When used in conjunction with other known clues, these measures provide an increase in probability of detection/classification.