(
A medical person measuring an extracted .22 LR bullet might report it as 5.56 mm. Just noting this possibility.
Formal metric designation for .22 LR is 5.6×15mmR, a difference of 0.0016", less than 2 thousandths of an inch possibly measured with bloody gloved hands.
)
Yes, it is starting to sound like a bad 1950s Hollywood or TV script. Or, later, a convoluted-evidence Perry Mason episode.