The takeaway here is that he’s actually received a Target Letter, which indicates a strong belief that there is substantial evidence against him and that criminal charges are being seriously considered. It’s a procedural step, and one that many people likely inferred, but it is important and shows a concrete stance on the investigation. It’s worth noting that “Target” is a specifically defined legal term in this context, on relevant part:
A “target” is a person as to whom the prosecutor or the grand jury has substantial evidence linking him or her to the commission of a crime and who, in the judgment of the prosecutor, is a putative defendant…
USAM 9-11.151
Despite overwhelmingly positive critical reviews, Children of Men lost money in its 2006 theatrical run. Most people I knew had never heard of it, and the only person I knew who had seen it was the friend I went to the theater with. It’s now generally regarded as one of the best films of the 21st Century (so far) and particularly lauded for its cinematography. It’s had a very successful home video run since then and is even more relevant today than on its release.