If you want to get a bit more cynical, you could very easily describe the deaths of Fred Hampton and the Freedom Summer murders as presidential assassinations. If you want to take the extra step down the rabbit hole, there's very real reason to suspect MLK was assassinated by the FBI.
Maybe Obama should have been charged, just to set the record straight, but likely this wasn't attempted because (1) Trump was too busy grifting to put any weight behind this, (2) all of those killed were on foreign soil, and (3) they were all working with Al Qaeda. This is getting into the realm of whether or not killing an enemy combatant is murder and what really defines an enemy combatant. I'm sure there was also pressure from both sides to specifically not answer these questions.
Either way I'd rather live in a country where a President gets charged after leaving office as a rule, than live in a country where a President can practically burn everything to the ground and walk away untouched.
Most presidents have done this. Whether it be bombing countries they're not at war with, trafficking drugs to enrich the war machine by arming enemies of the state, or invading foreign countries and committing war crimes based on their own manufactured lies.
Fun fact. We haven't officially declared war since 1941.
Korea, Vietnam, Kosovo, Afghanistan, Iraq, Syria, Yemen, Somalia, Libya, and now Ukraine? All NATO led military interventions or AUMF policing actions. No articles of war required.
trafficking drugs to enrich the war machine
One of the craziest "America just be like that" stories I've ever heard was the time Bush Sr set up a drug buy right outside the White House, by having the DEA extort a teenager picked up for selling crack on the opposite side of town to show up on Pennsylvania Avenue the night of a State of the Union Address and do a straw sale to another agent, just so he could talk about it on national TV an hour later like it happened organically.
Bush dangling a bag of crack on national TV and saying in his Father-Knows-Best voice that we need to go full-on Phoenix Program across every major American city, because of his little kabuki crack sale, is one of those "burned into my conscience" factoids that really changed how I saw our country operating.
So, yeah, in the long term we definitely need to put some guardrails on this. Short term, though, I say rev up those predators and go looking for whatever billionaire's yacht Coney Barret, Kavanuahh, and Roberts are chilling on