A man charged with murder in a 40-year-old death in Cass County has pleaded guilty. The prosecutor’s office says Raymond Richmond killed his cousin, Robert Stasiak, in 1977. The death was originally ruled a suicide, but in January of this year, a volunteer group called Seeking Justice began looking at the cold case again, leading to the charges. Richmond has pleaded guilty to second degree murder in the Ontwa Township death, which was the result of a shooting. As part of the plea deal, he’ll be sentenced to between 12 and 18 years in prison. A gun charge was dismissed. Sentencing will be September 15.