As someone who's lived in the Cedar Falls/Waterloo area for multiple years, I had never heard this story until recently.

And given the brutality of the acts that took place and our society's infatuation with true crime, I may or may not have been in a small state of bewilderment following reading about these murders.

On Halloween Night, 1975, in Cedar Falls, 25-year old Leslie and Jorjean Mark along with their two small children were shot to death. It's believed that Les' older brother, Jerry, committed the crime.

Leslie, who was younger than Jerry, was chosen by their parents to inherit the family farm -- a sign to detectives that Jerry may have gone through a jealousy-filled rage and found a reason to kill his brother and young family.

The dawning of the 'Cain and Abel' name for the killing came due to its similarities with the Biblical story -- killing one's brother over property.

This wasn't the only piece of evidence used to convict the older of the two brothers, though.

According to medium.com, "The second piece of evidence that caught the eye of the police was that Jerry had bought bullets just like the ones used in the murder shortly before the killings."

The site adds that Jerry had lied to the police about his specific whereabouts the night of the murders, and DNA evidence at the time linked the saliva on a cigarette butt found on the scene back to Jerry.

Ultimately convicted of the crime and sentenced to life in prison, Jerry maintains his innocence today. Though he has appealed the ruling multiple times, not much has resulted in the constant attempts to overturn the initial judgment.

"The consistent appeals did bring Jerry some success in 2006 when a judge ruled that the case should be retried, or that Jerry should be released, given the complete facts of the case. However, the new judgment from 2006 did not amount to much because a three-judge panel ruling soon overruled it after the state appealed the case."

"Even the cigarette butts that Jerry Mark had been pointing out to showed that the person who smoked them had type-O secretor blood, the same blood type as Jerry Mark himself. Hence, even the DNA analysis could not absolve the murderous brother from his guilt."

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