It used to be that if a victim survived an injury for one year, the assailant would/could not be charged with murder. Tough case. But for cripes sake, the original sentence was way too light.
A year a day used to be the common law standard for most of American history. That began to be eroded by states in the 1990s. Finally, in a 2001 Supreme Court case, Rogers v. Tennessee, the Court held that the ending of these common law prohibitions of ‘a year and one day’ was not a violation of the Ex Post Facto clause or other due process protections. So, the flood gates were opened to these kinds of decades-long ‘delayed murder’ cases.
The most famous one was likely the Brady case from Reagan’s assassination attempt. When Brady finally died in 2014/2015, the state of VA found the cause of death to be ‘homicide.’ The feds declined to prosecute because of the previous finding of mental incompetence from his first trial.
Yeah, I see this as a form of double jeopardy.