Crash investigators do this for a living?

When my friend had his motorcycle accident the police officer said he was traveling at an estimated 110 mph. The accident happened roughly 50 yards after a hard turn and there is no way he got up to 110 in that span. Similar situation to yours where no one else was involved to the investigation didn’t matter much but it made me question how they got that information. One officer told me that the speedometer was at 110 on the bike. Does anyone know if the speedometer stays at the speed someone was traveling when the accident happened?
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When the wheel left the ground it may have been free spinning at a hundred and ten when it crashed.
Never heard of any documentation on your speedometer saying what speed you were going in a crash after the crash.