There's security camera video of it going in, the third video in this report:
2 Killed When Learjet Crashes In Carlstadt, N.J. « CBS New York
It's hard to tell but it seems to be at a high bank-angle (80-90 degrees) and say 40 degrees nose down. Perhaps consistent with the speculation above?
Lots of comments about the wind, many of dubious import, but one obvious observation is that the wind could have caused a misjudgment as to the turn, followed by the overcompensation described above.
But speculation is probably pointless; presumably this will be one that the NTSB/FAA can figure out.