Do I need a cover letter?

Hi all so I had the good fortune of having a recommendation for a job by someone well connected at the company I was looking to work for. I have already had a phone interview and will be going in for an in person interview next week. I was told to bring about 5 copies of my resume since there will be multiple people interviewing me. Should I write and bring a cover letter as well? It is my understanding that those are more for the initial application than for later in the hiring process.

Looking forward to see what everyone has to say, thank you in advance.