Invalid Fair Catch Signal???

[JarMan69]

On a pop up kickoff, the second tier player on the receiving team caught the ball, gave a fair catch signal and took a knee in this order. What if anything would you have?? Please reference rule # or AR # thanks.

[TexDoc]

On a pop up kickoff, the second tier player on the receiving team caught the ball, gave a fair catch signal and took a knee in this order. What if anything would you have?? Please reference rule # or AR # thanks.

No foul.  The ball becomes dead as soon as the signal is given, regardless that the catch preceded the signal.  See below.

2-8-1-c:
A valid or invalid fair catch signal deprives the receiving team of the
opportunity to advance the ball. The ball is declared dead at the spot
of the catch or recovery or at the spot of the signal if the catch precedes
the signal.

[ElvisLives]

And that is an invalid fair catch signal, so he does not have the protection that a valid signal would provide.  If he got tackled while he was moving to take a knee, there would be no foul by either team.  He would have the same personal foul protection that any ball carrier would have, i.e., targeting, late hit, etc.

Robert

[Joe Stack]

player on the receiving team caught the ball, gave a fair catch signal and took a knee in this order.

Not sure what you're asking here. Nothing you described here is illegal. You can even add "valid" or "invalid" in front of "fair catch" and it would still be fine.

[Cowman52]

Ball is going to be dead as soon as caught, period. Receiver gets blown up, its going to be 15 and probably an ejection for spearing at best. 
  We are supposed to clean this game up not look for an excuse to look the other way.

[mccormicw]

However, the original question had the player catching the ball before signalling so until he signaled or took a knee, the ball is alive.