Motivic Galois representations valued in Spin groups

Let m be an integer such that m >= 7 and m equivalent to 0, 1, 7 mod 8. We construct strictly compatible systems of representations of Gamma(Q) -> Spin(m) ((Q) over bar (l)) spin ->(spin) GL(N) ((Q) over bar (l)) that are potentially automorphic and motivic. As an application, we prove instances of the inverse Galois problem for the F-p-points of the spin groups. For odd m, we compare our examples with the work of A. Kret and S. W. Shin ([18]), which studies automorphic Galois representations valued in GSpin(m).