  The $B^0$ meson decay modes $B^0 \to D^{*-} p {\bar p} \pi^+$, $D^{-} p {\bar
p} \pi^+$, ${\bar D}^{*0} p {\bar p}$, and ${\bar D}^{0} p {\bar p}$ are
studied in a sample of $124\times 10^{6}$ $B{\bar B}$ pairs collected with the
$BaBar$ detector at the PEP-II collider. The decay of $B^0 \to D^{-} p {\bar p}
\pi^+$ is observed for the first time, with a measured branching fraction
${\cal B}(B^0 \to D^{-} p {\bar p} \pi^+)=(3.80\pm 0.35\pm 0.46)\times
10^{-4}$. The following branching fractions are also determined: ${\cal B}(B^0
\to D^{*-} p {\bar p} \pi^+)= (5.61\pm 0.59\pm 0.73)\times 10^{-4}$, ${\cal
B}(B^0 \to {\bar D}^{*0} p {\bar p})= (0.67\pm 0.21\pm 0.09)\times 10^{-4}$,
and ${\cal B}(B^0 \to {\bar D}^{0} p {\bar p})= (1.24\pm 0.14\pm 0.12)\times
10^{-4}$. In each decay mode the invariant mass spectra of the charmed mesons
and the baryons are compared with a pure phase-space hypothesis in order to
gain insight into the $B$ meson decay dynamics. In particular, the Dalitz plots
of ${\bar D}^{*0} p$ versus ${\bar D}^{*0} {\bar p}$ for $B^0 \to {\bar D}^{*0}
p {\bar p}$ and of ${\bar D}^{0} p$ versus ${\bar D}^{0} {\bar p}$ for $B^0 \to
{\bar D}^{0} p {\bar p}$ are presented. All results are preliminary.
