Donald Trump entered a Manhattan courtroom and pled not guilty to 34 crimes.

It's one step in a long process that will likely lead to the first criminal trial of a former US president.

Trump acted in unprecedented ways, and now there is an unprecedented response to how he acted.

Trump lost the 2020 election and left office in January of 2021...

and since then, lawyers have been gathering evidence in 4 separate criminal investigations.

They are trying to figure out if Trump broke the law...

and if he did, what to do about it.

To understand these 4 different cases,

you need to know a little bit about how criminal investigations in the US work.

In the first phase, investigators gather evidence.

They might interview witnesses, review surveillance footage, comb over financial records or review texts and emails.

They show that evidence to a randomly selected group of citizens called a grand jury.

The grand jury's job isn't to decide if anyone is innocent or guilty.

They just listen to the evidence and basically decide if it makes sense.

If 12 of them think it does, they'll issue an indictment.

Only then can the prosecutor file charges.

The accused can plead guilty, in which case the whole thing goes straight to sentencing.

If they plead not guilty, then the case goes to trial,

and a jury hears the evidence

and has to come to a unanimous decision one way or the other.

Obviously, a simplification

and there's a ton of variations in different states and jurisdictions,

but that's the gist.

So where do things stand with those four Trump investigations?

Let's start with the hush money.

The state of New York has officially charged Trump with falsifying business records in the first degree.

In its statement of facts,

the prosecutors write that he repeatedly and fraudulently falsified New York business records

to conceal criminal conduct that hid damaging information from the voting public

during the 2016 presidential election.

This bank statement from Trump's former lawyer, Michael Cohen, shows that he withdrew funds in October of 2016.

He then used that money to pay an adult film actress

to stay quiet about an affair that she said she'd had with Donald Trump a few years earlier.

A year later, after Trump had won the presidency,

he wrote several checks to reimburse Cohen.

In his accounting records,

Trump designated these as payments for legal services,

which isn't exactly accurate.

This is some of the evidence that led to Trump's recent indictment and his not guilty plea.

In order to convict Trump of a felony,

the district attorney, Alvin Bragg,

he has to prove not just that he falsified these records in order to cover up the payments

but he has to prove that he did so in order to advance or cover up some other crimes.

But I think that these particular allegations against Trump

are pretty far afield of the really serious allegations that justify going after a former president.

You know, the allegation that he tried to steal an election.

"In Georgia, the votes are still being counted."

"CNN has just projected President-elect Biden the winner in Georgia."

"I believe that the numbers that we have presented today are correct."

There is a phone call between Donald Trump and Brad Raffensperger, the Secretary of State of Georgia,

the top elections official in Georgia.

The people of Georgia are angry.

The people of the country are angry.

And there's nothing wrong with saying that, you know, that you're recalculated.

You should want to have an accurate election.

And you're a Republican.

We believe that we do have an accurate election.

No, I... No, you don't.

No. No, you don't.

You don't have... Not even close.

Look. All I want to do is this:

I just want to find... uh, 11,780 votes.

If they magically came up with 11,780 Trump votes that didn't actually exist

that would have been enough to steal the election in Georgia.

A special grand jury in Georgia has heard the evidence and recommended multiple indictments.

But we don't know yet if District Attorney Fani Willis is gonna take things further.

The Georgia team isn't the only one trying to figure out if Trump's behavior after the election broke any laws.

Federal special counsel, Jack Smith's team is looking into similar questions.

There's been a lot of attention on this question of fake electors.

The state's electors cast their votes for whoever won the most votes in their state.

If Biden wins the state, then Biden's electors win the state and he gets that many electoral votes.

The Trump team wins key swing states.

They tried to assemble slates of alternative electors, even though Biden won the state.

They were asking me to facilitate having the electors meet and sign some sort of document.

This people were going to be in violation of the lockdown,

sneak in and stay overnight,

and then allegedly kind of cast their vote in the Michigan Capital.

Security wouldn't let them in,

so they signed the document in the basement of the state's Republican headquarters,

then sent it off to DC.

Trump's team led similar efforts in six other states where Biden won.

A grand jury in DC has been hearing evidence in this case for months, but they haven't voted yet.

But we appear to be in the closing stages of this.

The same special prosecutor is also looking into a fourth case against Trump.

"Unprecedented FBI search at the home of former president Trump."

"Trump's Mar-a-Lago property..." "...has been raided by the FBI."

This inventory list from the raid shows that they found dozens of documents labeled classified, confidential, and top secret.

There's a Washington Post report last year that some of this involved nuclear documents.

There has been some reporting that some of these related to intelligence that could have exposed certain US informants or sources...

And that basically the intelligence community did consider this really important stuff that should not have been hanging out at Mar-a-Lago.

Right now, a grand jury in DC is still hearing all this evidence.

As president, Donald Trump didn't just say outrageous things.

He acted in ways that no president ever had before.

Now that he's no longer in office, it's time to figure out if any of that unprecedented behavior was also illegal.

And if it was, what to do about it.