Last week, the ABA presented a panel discussion, When Good Lawyers Make Bad Decisions, moderated by Serina Vash, now executive director at NYU Law and a former prosecutor in the US Attorney's Office in New Jersey.
The panelists consisted of an acting FBI agent and three formerly-licensed lawyers, all of whom pled guilty to felonies. Each of these ex-lawyers had not only impeccable pedigrees (Princeton, Columbia, Univ. VA/London School of Economics), but were highly successful in their respective law practices, at least, up until the time the troubles for each of them began.
And their troubles began, tragically, as the consequence of enormous pressures in their personal lives; in one case, a lawyer was dealing with an alcoholic wife who eventually died as a result of her addiction.
In US: must be an attorney licensed and in good standing in any state, territory or DC.
Outside US: must be a lawyer or equivalent (eg counselor, barrister, advocate, solicitor), duly educated and licensed/accredited and in good standing.
As a general rule, experienced and currently practicing lawyers are more likely to be admitted.