Yet another backcourt violation question

[ATXCoach]

I always thought I knew the rule, but now I'm second guessing myself.

Player A1 in the front court with the ball passes to A2. A2 is running up from behind the play and attempting to establish front court status before catching the ball.

Is it a backcourt violation if . . .

a) A2 catches the ball while in the air with both feet last touching the court in the backcourt?

b) A2 catches the ball with one foot down in the front court and the other foot in the air, but last down in the backcourt?

FWIW, I always thought violation on both.

Thanks in advance!