  In a variety models of neutrino masses and mixings the lighter top squark
decays into competing R - parity violating and R - parity conserving channels.
Using Pythia we have estimated in a model independent way the minimum value of
P $\equiv$ BR($\widetilde t_1 \to c \widetilde \chi_1^0 $) $\times$
BR($\widetilde t_1 \to l^+_i b$), where $l_i = e^+$ and $\mu^+$, corresponding
to an observable signal involving the final state
  1$l$ + jets +$\met$ (carried by the neutrinos from the $\tilde \chi_1^0$
decay) at Tevatron Run II. For the kinematical cuts designed in this paper P
depends on $m_{\widetilde t_1}$ only. We then compute P for representative
choices of the model parameters constrained by the oscillation data and find
that over a significant region of the allowed parameter space P is indeed
larger than $P_{min}$. This signal is complementary to the dilepton + dijet
signal studied in several earlier experimental and phenomenological analyses
and may be observed even if BR($\widetilde t_1 \to l^+_i b$) is an order of
magnitude smaller than BR($\widetilde t_1 \to c \widetilde \chi_1^0$). The
invariant mass distribution of the hardest lepton and the hardest jet may
determine $m_{\widetilde t_1}$ and reveal the lepton number violating nature of
the underlying interaction. The invariant mass distribution of the two lowest
energy jets may determine $m_{\widetilde \chi_1^0}$.
