Police detectives and federal investigators tend to be very good at their jobs. They have powerful surveillance laws backing them up. Do you really think that they need your help?
It is possible, of course. You might be a good negotiator, analyst or investigator. However, it is generally wise to cautiously approach any type of contact with law enforcement personnel. That includes calls for assistance.
Investigators use a variety of different strategies to uncover information. In short, there is a human element as well as a technical one to their work.
Agents from the FBI, the local police and anything in between might try to persuade you to violate your rights. They do not have an obligation to tell you if you are under investigation or suspicion, in some cases.
Here is something else to think about: Why are you special? The government is responsible for overseeing millions of people. If they need help, there is probably a more efficient way to get it than making personal appeals.
It might feel good to know that important government officials value your input. However, it is important to know why they want it. Do they consider you an expert? Are they looking for evidence to build a case against you?
Again, it is wise to approach any potential cooperation with caution. A bad agreement with investigators could have the same effect as a bad business deal: serious professional and personal setbacks. Generally speaking, you should understand the whole situation before agreeing to help — or before even admitting that you might be able to help, for that matter.