Hit Bethany over the head with a shovel unintentionally thinking she was Alison.
Buried Bethany thinking she was Alison and that Spencer had hit her.
Bethany Young's Killer was previously an anonymous character, but later to be revealed as Melissa Hastings. It was later revealed that Mona Vanderwaal had hit Bethany before Melissa buried her alive.
Appearances
Season 4 (1)
Unbridled (Spencer was later to have not killed Bethany)