In the previous thread, someone had speculated that the glass might be glass bottles used for evidence collection. I don't work in a crime lab, just a research lab, but I can tell you that if we have a choice between glass and some other material, we always choose the other.

we live by the rule that "if it can be broken, it will be." :innocent:
Re:the baby monitor being turned off or not...when I was doing eletrophysiology with multiple-channel amps and speakers, if we had a mismatch between the channels (eg., amp set to channel 1 and spkr set to ch2), we would get static, as others have mentioned happens with baby monitors. I have only worked with 2 systems, but they both worked this way, and I ASSumed that it was a rule in electronics or audio. If so, maybe the abductor wouldn't need to be familiar with baby monitors per se, just with electronics or audio systems in general.