Homological vanishing for the Steinberg representation

For a field $k$, we prove that the $i$th homology of the groups $GL_n(k)$, $SL_n(k)$, $Sp_{2n}(k)$, $SO_{n,n}(k)$, and $SO_{n,n+1}(k)$ with coefficients in their Steinberg representations vanish for $n \geq 2i+2$.
Comment: 21 pages, 1 figure; major revision; to appear in Compositio Mathematica