My response to that question, spoilered for those who haven't seen it:
Spoiler!
I can't help but believe they are innocent. No DNA evidence in the garage, the damning evidence (read: planted keys) going unnoticed out in plain sight for over a week.. the blood vial and evidence box being tampered with... Brendan's "confession" was so forced it's unbelievable that a jury would think anything otherwise. His own lawyer colluding with the prosecution while being videotaped.
Steve is no angel, he may be capable of murder (apparently he doused his cat in oil and threw it on a fire) but the lack of evidence was overwhelming IMO and I don't think he killed that girl.