I mean in Target: UCAS, MitS, and some other books there's a recurring theme about a magical eqv. of the MRA always looming.
Anyway, as a general rule for the UCAS let me see ...
FBI. General federal jurisdiction for magical crimes through the Paranormal Affairs Division.
ATTF regulates telesma and one would suspect that extends to any physical items. They may come into play more often than one might expect because they'd be the ones regulating talismongers.
DEA (That would the new Drug Enforcement Agency intrduced in Runner Havens) might have a BAD division even if it involves relatively benign magical drugs (given the DEA's oversight of prescription narcotics now).
There is also the Department of Justice Magical Security Task Force. It's comprised of representatives of the FBI, KE, LS, DIMR, Tír Tairngire, NAN, a bunch of universities across the globe, and was formed to prevent more Bug Cities, etc. Since it was introduced in Target: UCAS one might expect other groups to liase with the MSTF, but it's rarely even been mentioned since that book. There may be a line in SoNA.
I think that's about it so far as canon has gone on to discuss. Anyway, some of this may come up in Artifacts Unbound. Some may come up in Conspiracy Theories since I'm writing the section on DeeCee. I have compiled a list so it's clear who's still around (which is not nearly as many as now IRL as I was reminded having just been back to D.C.), but ... Who knows. Generally speaking the only feds who are said to be around are the FBI and Secret Service (How the Secret Service is still around is a g-d miracle) with the occasional references to ATTF, DEA, Matrix Marshals, or Army CID. IRS has a law enforcement division, but it's only been listed as an intelligence agency (which is awesome) in Runner Havens. Actually, same with DEA and Homeland Security. So it's same to assume there are some that do both (FBI is a member of the intelligence community. So is DHS. DEA has a division that was admitted to the IC only like a year or two ago).
Oh oh oh.
I forgot about Interpol. Today, INTERPOL is at best a global intelligence agency or really mostly just a clearinghouse for criminal intelligence and such. Shadowrun's Interpol (note the case difference) is a full-blown SR version of SHIELD. When it was introduced, or revamped or whatever, in Cyberpirates! their agents really only operated where no one could tell them "no," or helped facilitate global efforts such as counter-WMD operations. However, they were agents, poorly supported and no going around invading countries. Ghost Cartels introduced the subsidiary, IDEA (which seems unnecessary. It could have just been a discreet division within Interpol) that eliminated any pretense that it's SR SHIELD. I'm not saying Interpol is or isn't operating (with sanction) in the UCAS (Well, I can't because I don't know.), but I am saying that I wrote the Texas Rangers so that GMs can throw them into literally any setting you can make up an excuse for them to appear—be it a police, espionage, or other role—then there isn't much stopping you from doing the same with Interpol, or even EuroPol, or C5, or the UN.