  The Balmer emission originated in the broad line region (BLR) of active
galactic nuclei (AGNs) could be either weak and difficult to detect, or even
absent, for low luminosity AGNs, as LINERs. Our goals in this paper are
threefold. First, we want to explore the AGN-nature of nearby type-1 LINERs.
Second, we aim at deriving a reliable interpretation for the different
components of emission lines by studying their kinematics and ionization
mechanism. Third, we intend to probe the neutral gas in the nuclei of these
LINERs. We study the 22 local (z<0.025) type-1 LINERs from the Palomar Survey,
on the basis of optical ground- and space-based long-slit spectroscopic
observations taken with TWIN/CAHA and ALFOSC/NOT. Kinematics and fluxes of a
set of emission lines, from H{\beta} to [S II], and the NaD doublet in
absorption have been modelled and measured, after the subtraction of the
underlying starlight. We also use ancillary spectroscopic data from HST/STIS.
We found that the broad H{\alpha} component is sometimes elusive in our
ground-based spectroscopy whereas it is ubiquitous for space-based data. By
combining optical diagnostic diagrams, theoretical models (for AGNs, pAGB-stars
and shocks) and the weak/strong-[O I] classification, we exclude the
pAGBs-stars scenario in favor of the AGN as the dominant mechanism of
ionisation in these LINERs, being shocks however relevant. The kinematical
properties of the emission lines may indicate the presence of ionized outflows,
preferentially seen in [O I]. However, the neutral gas outflows, diagnosed by
NaD, would appear to be less frequent.
