Why do you want to catch and release?

    I have trapped a feral cat twice in a safe trap.  The lure of
food can be very strong.  You might have better luck if the trap is
disguised some way, like wrapping a blanket around it.  The cat may
even feel more safe going into what appears to be a cozy shelter.  
Expect the cat to be very angry at having been caught again.  When I
caught Jetadiah the second time in the same trap he had some very
nasty things to say to me.(;-))