Example 1: In countries that had little formal legal structures and rudimentary identification (e.g. India in the early 1800s), it was incredibly easy to be a criminal and just move from town to town while acquiring new identities. In other words, there was a huge upside to becoming a career criminal since it was both difficult to catch you (no forensic evidence) and even if you were caught, you could just reboot your life.
Example 2: He mentions a case where a gentleman was charged TWICE for crimes that were later found to have been committed by someone else who had only a passing resemblance.
I read this book before Twitter/Facebook became ubiquitous and every like, share, comment was public knowledge but even at the time, it was mind boggling how different "identity" was back then.
If you plead the 'benefit of the clergy', you were branded, so you didn't do it again.
I was watching a show on TV last night where they were minutely examining a newly discovered photo of Lincoln to see if it was really Lincoln or someone else. One analyst gave it an "85% probability it was Lincoln".