The point of hiring a defense attorney is to safeguard your civil rights and achieve the best outcome when facing a possible conviction. In order to achieve this, you not only have to hire a good defense lawyer, you should also follow their professional legal advice. Clients who do not follow the advice of their lawyers might end up regretting their decision. Just take Martin Shkreli for example.
Shkreli gained notoriety as the pharmaceutical CEO who jacked up prices of a life-saving drug 5,000 percent. However, he was arrested for federal securities fraud in an unrelated matter back in 2015. Shkreli was charged with taking $11 million from one of his pharmaceutical companies to pay back the money he lost through bad trades via a side business hedge fund.
His defense argued that he had good intentions, and were considering the idea of putting him on the stand to testify to his own character. Unfortunately, instead of taking his lawyer's advice to not discuss any details of the case publicly, he took to social media regularly to defend himself. He mocked journalists and critics alike to the point where he was likely antagonizing the judge and the jury, and certainly hurting the case of his defense.
Shkreli undid his own lawyer's work by mouthing off on social media. If you're going to hire a defense lawyer, it's important to understand how following (or not following) their advice can affect your case.