While Perry Mason, Della Street, and Paul Drake were first discussing what to do with the baby, the shadow of a boom microphone can be seen briefly, upper left corner.
Perry, Della, and Paul are discussing what to do with the baby and examining items left behind, including a note and a St. Christopher's medal. Paul says he can have the note checked for latent (finger) prints right after both he and Della had been handling it and right before he takes the medal and puts a big thumbprint on one side (as had Della).