Do not try to explain your way out under pressure.
Investigators may sound calm, friendly, or practical. The purpose of the interview is still to gather information. A statement given before counsel is involved can become the government’s most useful evidence.
Use clear rights language.
A clear invocation is: I invoke my right to remain silent. I want an attorney. I do not consent to any searches or seizures. After invoking, stop talking about the allegations.
Do not help build digital evidence.
Do not provide passcodes, unlock phones, identify apps, locate messages, or explain screenshots without legal advice.