Blimey
.450/400 Nitro Ex
Maybe.If Trump handed this over to Justice Department he would be accused of abuse of power, using the government agency against his potential opponent.
There is also another option: He could have just done nothing. If nobody else was pushing for it, maybe he could have let it go, or been ab it more strategic about it and make waves and try and encourage other people to make it a media spectacle, thus giving him or the DOJ more credibility in pushing for it.