What did you get arrested for? If it's a DUI or driving related and you failed the breathalyzer then yes. If you didn't fail the breathalyzer then No youn dont haven to tell them shit! It's called innocent until proven guilty. Just spend the extra money and higher a good lawyer!! If you're found guilty then you would have to tell them.
If you didnt fail the sobriety test then you would not be arrested idiot, and it's Hire a lawyer, this is honestly why Frx is the motel 6 of pharma industry