Translation:This is perhaps the reason for her arrest.
The old rule was that este is accented when it is used as a pronoun (e.g. éste es un libro). It remains unaccented when used as an adjective (e.g. este libro).
Now this practice is not longer really followed, so it is perfectly acceptable to use an unaccented este as a pronoun (e.g. este es un libro).
I have the same question.....I have been told subjunctive should be used when there is doubt, uncertainty, subjectivity, etc and "perhaps" is pretty much expressing uncertainty and doubt so....it is confusing when this is not done in DL and seems arbitrary ( sometimes subjunctive is used when it's not clear it should be and then it is NOT used when it seems obvious)....BUT it seems that "ser" is used in the indicative form when it is part of the reason for the doubt ie in "ES posible que Victoria estudie espaniol" the "ser" is indicative but the "estudiar" is subjunctive so maybe that is the rule - ie when ser is part of the reason for the subjectivity or doubt then it has to be indicative ie to confirm that there is doubt....