]because tripti ne tanya se dhokhe se proprety hasil ki aur ho sakta hai tanya ne tripti ko mara ho, i think tanya can see what she is pretending and think that tripti saari properti karan ke naam kyon karti. i think tanya might have forced her to sign properti papers to karan's name.
EXACTLY.Even i am thinking on the same lines.Tanya is surely pretending to b blind.Morever the killer has to b sme1 we were not expecting and that is Tanya. Also it wud b a gud way for Tanya 2 leave SN by going to jail.