What is the strangest mystery that is still unsolved?

In 1976, residents of the small city south of Columbus Ohio began receiving handwritten sinister and graphic letters. Each letter included secret and dark details about their personal lives.

One resident received a ton of letters, accusing her of various unsavory acts. The author warned the resident that he had been keeping an eye on her home, as well as her comings and goings. The resident was horrified and tried to keep the letters a secret until her husband began receiving them.

The attacks on the family continued, with large posters appearing around town spreading rumors about their 12 year old child. One day in 1977, the husband left the house after receiving a call from who he thought was writing the letters. A few minutes later, the husband was found dead at the end of the street dead behind the wheel. The sheriff had ruled it a homicide when he realized that a single shot had been fired before the accident, but there was no evidence that the husband was shot at the site. The sheriff found the husband was twice the legal limit and ruled it a drunk driving accident.

The letters began once again, this time accusing the sheriff of covering up the true nature of the death. The letters also accused the sheriff of mishandling an investigation into the county coroner who had been accused of other grotesque acts.

The harrassment continued, this time with signs along the road and in 1983, the original resident who had been accused of having an affair pulled over to remove a sign. During the effort to remove the sign, she discovered a box was attached and inside of it was a small pistol. The gun was part of a booby trap designed to fire when the sign was removed.

Paul Freshour was arrested and given 25 years...but one small problem. The letter writing continued even after Freshour was put in jail.

In a new batch of letters, the author had promised to dig up the grave of a deceased baby and mail the bones to the police in the case of another potential affair turned murder.

Hundreds of residents continued to receive personal letters until 1994 when everything stopped.