  Entanglement between spatially separated electrons in nanoscale transport is
a fundamental property, yet to be demonstrated experimentally. Here we propose
and analyse theoretically the transport statistics of a generic spin entangler
coupled to a hybrid quantum dot-ferromagnet detector system. We show that the
full distribution of charges arriving at the ferromagnetic terminals provide
complete information on the spin state of the particles emitted by the
entangler. This provides means for spin entanglement detection via electrical
current correlations, with optimal measurement strategies depending on the a
priori knowledge of ferromagnet polarization and spin-flip rates in the
detector dots. The scheme is exemplified by applying it to Andreev and triple
dot entanglers.
