Well, not an axe-murderer, but possibly a serial killer…
Al Gentry spent 25 years trying to find out who killed his brother. His investigation turned up that his brother’s wife left behind a trail of five dead husbands. She was ultimately charged with solicitation of his murder, but died before she could be tried. Investigators were never able to build a case against a shooter, nor were charges filed in the other deaths, though several of them are suspicious. It’s a crazy story and a good read: http://www.foxnews.com/us/2013/07/17/nc-man-whose-long-search-for-brother-killer-led-to-elderly-georgia-widow-has/?intcmp=obnetwork
crimcourts : A Criminal Law Blog 