Should this phrase be contained in commas, parentheses, or nothing?

I tried to figure out if this is correct. I just don´t know if I should use commas before and after "rather than one", a parenthesis, or no comma at all.

I think that "rather than one" is non-essential information and it is not part of the object "three consecutive adjectives alike". Am I in the clear?

Since the writers used three consecutive adjectives alike, rather than one, and highlighted the noun “MURDER”, a negative attitude towards non-standard behavior is communicated to the reader.