Say an fbi special agent wanted to enter a state prison to interview a suspect known to be working with a crime organization. too my knowledge he has jurisdiction as a federal agent to investigate a federal suspect. a friend of mine thinks otherwise. anyone able to ? (sorry for putting it in the business category, no law category is there so thats the closest i can get.

49 points and no one answered!? Not even a crumby answer? I can't believe it.

Let's start with something very general, and this is just from the top of my head. I always thought that the FBI only took on cases that were interstate in nature. In other words it meant that the local authorities had their hands tied because they only had power in their own jurisdiction.

If it was true, I don't think it is any longer. It really does depend on the nature of the crime. Here's what I can say.

The modern FBI doesn't do what it used to do during the depression. In those days, its mandate was to track down wretches like Bonny and Clyde and John Dillinger.

Today its modern mandate is to track down terrorists, foreign and domestic. In a write-up about them, they use the 2015 McDonald's attack which killed 14 innocent people and wounded 22 others. The couple who did the murdering and wounding were influenced by foreign terrorist groups. So the investigation didn't stop with the murders. The FBI dug deeper to see who was really the root cause. The article was silent about what was done.

Domestic Terrorism is a terrible thing where citizens turn on each other. I use someone like Timothy McVey as an example. If you have a beef with government officials, that's one thing. Making 5 year olds a victim is quite another. The FBI didn't stop until they had the full story. You may think it is tainted: that is your right, but they were not inactive.

Counter Intelligence. This is another nasty piece of work. It usually involves finding people who are willing to sell military of industrial secrets for money or recognition. The FBI is mandated to go after such people and in cooperation with the DOJ make sure that America is protected from such people. Canada (where I live) has cases that come out of the late 40s early 50s. One of the most famous was the Igor Gouzenko case which I leave you to look up. I'm not sure what Gouzenko's motive was. I was quite young when he hit the headlines, so to get a full picture, you'll have to look it up. I remember it, but not the details. Along with the Mounties, I'm sure the FBI was involved.

Cyber Crime of all the crimes that are around, this is probably the one I hate the most, because it involves the misuse of knowledge that could be put to much better use. A subcategory of this is ransomware which has had hospitals, schools and large and small businesses held up for money. Can you imagine what would happen if someone came into the ER and the hospital couldn't access his blood type because morally literate person locked up the information. The FBI is mandated to handle such things.

Pubic Corruption. This has a very long history and you could pick almost anything as an example. My favorite is JP Morgan (the Bank not the person). They have for 2 decades been the king pin of criminal banking crime and are just now being threatened with actual jail time. In the past few years, they have paid upwards of 30 billion dollars in criminal activity. I guess they consider that the cost of doing business, because they have always settled  the fine. But this is a serious example of public corruption because 30 billion dollars is not a trivial sum even for a bank, but apparently their piggy bank is full enough that 30 billion is a coffee at Starbucks for the rest of us. I'd like to explain more about this, but it is no Bonny and Clyde case. White collar crime is very complicated.

You can add organized crime to this list. I've often felt like sending the IRS a tee shirt that says "We got Al Capone, and we can get you." The FBI played a signficant part in bringing down Capone.

Well that goes someway to tell you what the FBI does. I hate to use a platitude, but I do hope it helps.