  We present experimental results for the ionization of aniline and benzene
molecules subjected to intense ultrashort laser pulses. Measured parent
molecular ions yields were obtained using a recently developed technique
capable of three-dimensional imaging of ion distributions within the focus of a
laser beam. By selecting ions originating from the central region of the focus,
where the spatial intensity distribution is nearly uniform, volumetric-free
intensity-dependent ionization yields were obtained. The measured data revealed
a previously unseen resonant-like multiphoton ionization process. Comparison of
benzene, aniline and Xe ion yields demonstrate that the observed intensity
dependent structures are not due to geometric artifacts in the focus. Finally
we attribute the ionization of aniline to a stepwise process going through the
pi-sigma^star state which sits 3 photons above the ground state and 2 photons
below the continuum.
