The stage before any charge
A theft investigation can be run by police, a prosecutor's office, an employer's internal team, or an insurer, and each has different goals. Police and prosecutors are deciding whether to charge, while an employer may mainly be deciding whether to end someone's job or seek repayment. A police request to come in and talk is usually voluntary, even when it is phrased as a chance to clear things up. What you say in that conversation can become evidence, and statements given without preparation often create problems that the underlying facts would not. In many cases there is still room at this point to shape what happens next.
Keeping your side of the record intact
Keep any card, letter, or message you received from investigators, along with the date it arrived. Save your own receipts, bank records, and messages that show how you came to have the property or money in question, but do not reach out to witnesses or the person who reported the loss to discuss it. If the matter involves an employer, keep your personal messages and pay records, and ask before copying any company files. Notes about what happened should be prepared for your lawyer, after talking with your lawyer, not on your own. Do not destroy or alter anything, even items that seem embarrassing or unrelated.
What counsel can do before an arrest
We can often find out what the investigation is about, who is running it, and whether you are seen as a witness or a suspect. In some matters it makes sense for a lawyer to speak with the detective or prosecutor on your behalf; in others, the safer course is to say nothing until more is known. If the dispute is really about a debt, a business partnership, or shared property, showing that early can change how investigators view it. Where an arrest seems likely, arranging a voluntary surrender can sometimes avoid an unplanned arrest at home or at work. Immigration status and professional licenses are part of the discussion from the beginning, because they affect which outcomes are acceptable.