I did a google search and found this webpage. Still nothing substantially mentioned, like type of device, etc. I suspect they are searching for folks other than the guy who owned the RV, but we will never know the facts.
Watch the video, focused on 1:42 timestamp and expand it to max screen. I put the cursor on the van that was supposed to be the device location, bullcrap. When the fireball shows a second or so after detonation the center of the fireball was about 10 feet toward the center of the street. They claim it arrived at I think 1:10 AM, and I am sure the video has been viewed to see if the driver exited the vehicle ( some reports say it was ANNOUNCED on the recording the bomb was in a building), besides the police is supposed to have been there well before zero time and didn't report anyone inside, or any other odd details. To me, the officers stories that were there, don't make sense. Why wasn't SWAT or a bomb team there actively checking things out?
I have seen several other angles, this video I hadn't seen before. BTW the large guy walking away lower left just before zero time was the black officer describing the scene that got knocked down, in case you don't want to watch the rest of the interview.
