  Metric type II solar radio bursts and solar energetic particles (SEPs) are
both associated with shock fronts driven by coronal mass ejections (CMEs) in
the solar corona. Recent studies of ground level enhancements (GLEs), regular
large solar energetic particle (SEP) events and filament eruption (FE)
associated large SEP events have shown that SEP events are organized by
spectral index of proton fluence spectra and by the average starting
frequencies of the associated type II radio bursts. Both these results indicate
a hierarchical relationship between CME kinematics and SEP event properties. In
this study, we expand the investigations to fluence spectra and the
longitudinal extent of metric type II associated SEP events including
low-intensity SEP events. We utilize SEP measurements of particle instruments
on the Solar and Heliospheric Observatory (SOHO) and Solar Terrestrial
Relations Observatory (STEREO) spacecraft together with radio bursts
observations by ground-based radio observatories during solar cycle 24. Our
results show that low-intensity SEP events follow the hierarchy of spectral
index or the hierarchy of the starting frequency of type II radio bursts. We
also find indications of a trend between the onset frequency of metric type II
bursts and the estimated longitudinal extent of the SEP events although the
scatter of data points is quite large. These two results strongly support the
idea of SEP acceleration by shocks. Stronger shocks develop closer to the Sun.
