Who killed Jenna in Pretty Little Liars?

Answer 1

Allison killed Jenna. but the Ali we all know from P L L is actually Allison's twin mental sister Courtney and when "Allison" ( aka Courtney) goes missing that night the real Allison kills Courtney and is the real "A" but the person who is sending the txts as "A" in the show so far (episodes 1-9) is really Mona V Hanna's BFF. And Jenna dies because Allison (the real one) tells her that her dog ran away and jenna went to chase it but actually ended up falling off a cliff and dying cause she is blind
Alison.