>>4323437It was a widely repeated older projection, but it's not a good description of the current estimate. The "one in three" figure came from a Bureau of Justice Statistics projection that if incarceration rates at the time continued, one in three Black males born then could expect to go to prison during his lifetime. It was a conditional forecast, not a count of what had already happened.
Human Rights Watch
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More recent estimates are lower: The Sentencing Project says one in five Black men born in 2001 is likely to be imprisoned at some point in his lifetime. So the claim reflects a real, historically cited estimate, but it overstates the newer projection.