The 37-year-old former commander of the 4th Guard Brigade's 3rd Imotski Platoon, was shot by Jozo Djuzel, 48.
The attack was preceded by an argument in which another man, Vinko Orec, took part on the side of Djuzel.
Djuzel and Orec were Bartulic's former comrades-in-arms and members of the local war veterans association.
Djuzel was arrested on the day of the incident, while Orec was arrested on Tuesday. The police pressed charges against Djuzel for attempted murder and Orec for inflicting grievous bodily harm. The charges are now expected to be changed.