My friend came across a criminal case. Is it useful to hire a lawyer? Can I reduce my sentence?

When lawyers intervene in criminal cases, they can avoid extorting confessions by torture, sue and appeal when criminal suspects are violated by law, and apply for bail for criminal suspects. The lawyer's greatest function is to collect and provide evidence favorable to the criminal suspect, and put forward the defense opinion that the criminal suspect is innocent, the crime is light or the punishment should be mitigated.