News or civilian footage would've been posted. There's no 'the networks chose not to show this on tv out of respect for the family of a police captain's daughter' or 'gosh, I remember this'. It's presented as if it had never been seen before.
Also, if the source were civilian or news, they'd have kept on filming and there'd be rebuttal footage of the Goblin circling Spider-man's head laughing his ass off (He was yelling, "She's dead, Spider-man! She's dead! The woman you loved is dead!").
In any case, Gobby admits to kidnapping her for a hostage. Legally, when a death occurs in the course of a crime it's considered the fault of the criminal.