I am not sure what you have experienced in murder cases you have handled; but in my experience and in the murder cases I have worked on multiple, sometimes dozens, of SW are issued, especially now with regards to electronic devices.
Often, some of the SW's do not produce evidence used in the prosecution. Just because a judge grant's a SW, especially in a murder investigation, does not mean incriminating evidence is found. In fact, sometimes in a murder case one SW produces incriminating evidence and another SW produces exculpatory evidence.
LE has to try to piece it together based on what they find. The SW itself is not evidence. It is an investigatory tool.
In this case any evidence gathered from the three known SW's would have been fully analyzed at this point in time. LE has whatever info that was procured during the SW's at their disposal right now to use as they see fit (more searches, arrest, prosecution)..IMO