Historical "Truth"
One warning: early newspapers were not exactly unbiased in their reporting. This is true of other primary sources as well. Memoirs and letters are particularly suspect. Writers have always slanted the accounts they've left behind to make themselves look better and to reflect their own opinions-or those of the people paying them to record events for posterity. Sir Thomas More's History of King Richard III (1513) is a case in point. More might have lost his head much sooner if he hadn't written what Henry VIII wanted to read about his predecessors.
It is unwise to leap to any firm conclusions based on records left by our ancestors. Let's say you've found a book that reprints a series of laws dealing with criminal offenses, passed in the time and place you're writing about. They were in effect, but did everyone obey them? Were they enforced? Did people living at the time, concerned with their own survival, away from the city or the court, even know they existed, let alone what they said? English law in the sixteenth century specified hanging as the punishment for a variety of crimes, including the theft of anything valued at a shilling or more. In case after case, this sentence was not carried out. Felons were branded instead, or acquitted in spite of overwhelming evidence of guilt. Then, as now, nothing is cut and dried. Historical "truths" can be interpreted in a variety of ways. You will need to use common sense to apply the realities of everyday life in a bygone age to the "facts" of history.
From Kathy Lynn Emerson. How to Write Killer Historical Mysteries: The Art and Adventure of Sleuthing Through the Past (pp. 44-45). Kindle Edition.