A lot going on this hour, but first we are focusing on the bombing investigation.

Our Susan Candiotti joins me with the breaking news.

What have we learned, Susan?

We learned from a federal law enforcement official who irregularly briefed on the investigation that images of two men there are two photographs we are talking about here,

are being circulated among law enforcement around the country and those agencies and law enforcement officers are being asked to beyond look out for these people because they are possible suspects, possible we emphasize and of high interest.

Now the reason we are being told that there is high interest in these people,

is because of the timing of where they were right near the finish line before the blast went off and also because of what they have with them what they are carrying.

In this case, at least one of them is carrying what appears to be a dark-colored back pack.

And they have also circulated a memo, so to speak among that agency and describe it this way.

It says attached photos are being circulated in an attempt to identify the individuals, highlighted therein.

Feel free to pass this around to any of your fellow agents elsewhere.

We know also that authorities do not yet know the names of these people,

so they truly are trying to find them and calling them possible suspects.

So let's be very clear and what we know and what we don't know.

You have actually seen one of these photos, one of these photos is in the possession, I believe or both of these photos.

I have seen them both.

You have seen them both.

They're in the possession of CNN, but we are not releasing them,

we are not showing them on the air because we don't want to do anything that would affect investigation in any way.

Exactly, because if we show them, they don't know who these are,

we don't want to be one part of tipping these people off.

We are also just for the record not going to any descripted information about the individuals in these photos.

We are doing that on purposes.

Exactly, that's right. Don't want to give too much way.

Ok. So again botteline, there are two photos of two individuals.

It's fair to call them person of interest, not even suspects, just persons of interest people that,

the law enforcement wants to talk to these people, wants to learn more about these people.

Would like to identify them by name and find them.

That's the latest.