History repeats itself..
And so does law, in the form of case law.
It also helps to know where some of our common laws came from. Its not necessary to study all of this- it all comes out in legal research anyways. Its just nice to have a better understanding as to the sociological side of things, which is where the history lessons come in.
Like- knowing about the women's movement, is not entirely law related- even though women ended up with the constitutional right to vote. Its still good to know all that women's suffrage and stuff, anyways- because then you can bring that emotional history into the courtroom, and move the jury to choose the verdict you want.
If it was a racial crime, it is good to talk about historical events like slavery, segregation, and the severe torture and killings of blacks in Texas and other southern states, around the turn of the 20th century, even midway through.. Including the assassination of Dr Martin Luther King Jr. That would move a jury to help find a guilty verdict in a case regarding a hate crime towards an innocent black person.
Consider crimes against gays- How many times do we see this in the news? It helps to bring stuff like this up- it is totally relevant to the case, if it helps the client, and the judge okays it- it should be discussed, for the jury to remember.
