It's also pretty common for family members to refuse to accept a verdict of suicide, altho it's true.In my experience, it's a slow and painstaking process to get the coroner to change the manner of death to undetermined if not homicide, and even slower to get an investigation reopened. IMO, somebody likely working for DC's son is working behind the scenes, hoping the release of the autopsy results will generate momentum and public support. As I said, a slow process....
I've seen some cases where the investigation is left open by LE for a looong time, perhaps until some forensic experts are able to take the time do to some tests/recreations of the scene, or research other similar cases.
It keeps the family hanging, but seems to make them more likely to accept a suicide verdict.
JMO