Top Law Schools

Hey all - just wondering if this is an acceptable practice: I am a 2L, and applied to ~5 big city DA's offices for summer internships between November - early January which I haven't heard anything from. I send all my applications by certified mail, so I know they were received. Is there any way to send these organizations updated resumes at this point? In a (very) transparent attempt to make myself more marketable I have been getting courtroom advocacy experience in several organizations, which isn't reflected in my submitted applications. My concern is that with the number of applications they receive that any miniscule bump would be offset by the faux pas of resubmitting - so I'm leaning toward not doing it.

Appreciate the advice.