Unity cannot play two webcams with same name

I have two web cameras and both are FaceCam 1000X, I’m trying to show each one in a WebCamTexture, but only the first that I play is working, the other throws the following errors:

Could not start graph
UnityEngine.StackTraceUtility:ExtractStackTrace ()

Could not pause pControl
UnityEngine.StackTraceUtility:ExtractStackTrace ()

This is an example of my code:

var tex1 = new WebCamTexture("FaceCam 1000X 1");
tex2 = new WebCamTexture("FaceCam 1000X");
_video1.texture = tex1;
_video2.texture = tex2;

Is there any way to handle this issue??