We know that:

1. in the gamma-dacay, photon carries parities of (-1)^L and (-1)^L+1 for electric and magnetic transition, respectively.

2. the parity is conserved in the gamma-dacay, hence the parity difference between mother and daughter nucleus should be responed by the parity carried by the photon.

and it is said that:

3. the photo has an intrinsic parity of (-1).

The question is:

Is the intrinsic parity of photon involved in the gamma-decay?