Nope, that was ammonium nitrate. He did use some diesel, and some nitromethane as a sensitizer but the exact one is not too important.
The original patent for ammonium-nitrate explosives used lampblack as the sensitizer, you don’t need oil per se. In England, the mix was called ANIS, they used icing sugar (confectioners sugar in the US) and ammonium nitrate. Wood meal, flour, and a bunch of other stuff including gasoline and diesel can be used. I have not seen data on it, but cooking oil probably works.
So if those cops were truly worried about someone blowing stuff up, they’d pull every hydrocarbon fueled car over and confiscate it.
Thanks, !