Another question for fellow Sleuthers - Why did Grandmother all of a sudden show up in the courthouse? Towards the end of trial - To get her used to the courthouse so when she begs the jury to save her lovely grand daughter's life in the penalty phase? Did Grandmother look at the photos today to see her grand daughter's handiwork?
I think that it's possible that she was a prosecution witness. The day that she arrived in court is the day that the defense argued to keep witnesses out. The grandmother was probably going to testify about the stolen gun. It's the one missing piece in the prosecution "tied with a bow" rebuttal argument.