They may but they do not have to.
Macy Jaggers's answer to a legal question on Avvo does not establish an attorney-client relationship. Ms. Jaggers offers everyone a free consultation to discuss their case. Feel free to call her office at 214-365-9800 to make an appointment (phones are answered 24 hours) or visit her website at www.macyjaggers.com for more information about her services and recent victories.
I have never seen prior notice sent out in my part of the state. Not to say it may not be happening elsewhere, but what I see most often is that the "flag" for a prosecution coming down the tracks is when the person getting benefits is interviewed by the investigator.
I would add that not all welfare fraud cases are hopeless. If your friend is expecting a welfare fraud charge, now is the time to be talking to criminal defense lawyers who have experience with that kind of case.
Answers on Avvo are for general information purposes only and should not be relied upon as legal advice. No attorney / client relationship is created by providing this answer. For specific advice about your situation, you should consult a competent attorney of your choosing.
They will most often contact your friend for an interview. At that interview, it will likely be recorded. Be aware that any incriminating statements made at that time will be used later. If the total amount is over $1,500, it will probably be a felony in Texas.