Katie is a female character and Oliver is a male character so you can choose either...

It depends... :)

Katie has fallen in love with two brutal psychopathic women also murders are so brutal with no mercy it makes Katie really fall for them but Katie will fall for you Suddenly even though you're not actually a psychopath and not a brutal killer...Maybe your look? Katie is attracted to you???... 

Katie falls in love with...
∆lice - The first person 
∆iden - Second person
You - The last person