Some was advised by an attorney if he didn't testify his witnesses couldn't either
That is untrue, a defendant in a criminal case can take the 5th amendment so as to not incriminate themselves, any witnesses they have can still testify as long as their testimony is otherwise admissible.
Legal disclaimer:This message does not constitute legal advice and does not create an attorney-client relationship. Any statements are made for general informational purposes and do not constitute legal advice. No attorney-client privilege is created by this communication. Attorney is licensed in California only.
Personal Injury Lawyer
Yes. But the testimony must be admissible. Hearsay is not admissible unless it falls w/in an exception to the hearsay objection.
Of course they can. As pointed out by the previous lawyer answering this question, all testimony must be admissible (i.e., relevant, non-hearsay, based on personal knowledge or qualified expert opinion, etc.) but no party to civil or criminal litigation needs to testify as a pre-condition to calling other witnesses. That said, and depending on circumstances not apparent from your question, the defendant may be best served by taking the stand. See a local lawyer who can provide you personal representation (if you're a party to this litigation).
"The law" is a very complex profession, and all specific legal questions will depend on a variety of facts that you may not think to include in your questions on this forum. I am not your attorney, and in answering your question you must understand that I cannot and do not give you legal advice upon which you are entitled to rely. At best, I hope that my answer, and others you find here, will give you a basis for better understanding of the issues you face so that you can provide complete information to a lawyer that you retain to give you advice and representation on which you can confidently rely.