Yea, the one you can't be denied is a public defender who sucks and only wants to plea you out. Don't lie is bad advice, good advice is don't speak at all; they are not your friends, and speaking at all allows them to lie about what you said and they don't have to prove anything to completely fuck your life up.

Don't assume they're the good guys looking to solve a crime, they aren't; they're thugs looking to close cases by whatever means possible and they don't care if you're actually innocent, they don't care about you at all nor do they care about the truth.