Charles Severance was convicted of three murders involving prominent Alexandria, Virginia residents which occurred over more than a decade in spite of the entirely circumstantial nature of the evidence against him and the existence of credible alternative suspects (archived, archived). The first murder to occur for which Severance has been convicted was that of Nancy Dunning, a real estate agent and wife of James Dunning, a former Alexandria sheriff. Her husband the former sheriff was a suspect for a long time though he was never charged in a crime.
All of the most damning of the circumstantial evidence presented to the jury in spite of defense objections was in Severance's personal writings, which had been described frequently as "eccentric" and political. Prosecutors reconstructed the context of the writings to damn Severance by framing the murders as political assassinations in the tradition of Cardinal Richelieu finding something within six lines written by a man with which to hang him. Of course the political assassination theory neglects motive for killing the real estate agent instead of killing the sheriff.
Prosecutors claimed to link the crimes through ballistics though three separate firearms were used for each of the three murders. They also claim that all of these homicides are linked by the use of a "rare" form of .22 caliber ammunition in spite of .22 caliber being exceedingly popular in homicides, a fact that would be known and available to a person familiar with law enforcement work who wanted to make his murderous hobby appear to be exceedingly common killings.
Whether Severance, the former sheriff, someone else, or some combination of them actually committed some or all of the killings, this case is instructive in the ways United States prosecutors manage to bend narrative and circumstance to secure convictions in the absence of anything resembling certainty.