Lester Holt

An arson investigator gives us the lowdown.

What did the smoke look like?

Where was it?

What were the flames doing?

But before all that, we're off to Columbus, Ohio, where police are on the hunt for a killer in the mysterious shooting deaths of a dentist and his wife.

It's a case that has captured national attention in these early days of the new year.

Turning now to a shocking double homicide in Ohio.

Police asking for the public's help to find a killer.

The double murder of Dr. Spencer Tepe and his wife Monique shot to death in their Wineland Park row house in the early hours of December 30th.

Their children left alive in another room.

Their cries heard hours later by someone who called 911.

It's been more than a week since Atepe's bodies were discovered, and the Columbus Police Department has remained tight-lipped about the status of the investigation, until now.

On Monday, they released security video that could hold the key to the killer's identity and why this young couple was gunned down in their own home.

Joining me now with the latest details is NBC News correspondent Ryan Chandler, who has been covering the case since the beginning.

Thanks for joining me, Ryan.

Lester, pleasure to be here.

To start, tell us about Spencer and Monique Tepe.

So, Ryan, can you lay out what happened on December 30th?

How did police find out that something was wrong?

Did police see any signs of forced entry, or did they find the murder weapon?