Police said the shooting happened about 8:15 p.m. in the alley behind the Frontier restaurant, located at 1072 N. Milwaukee Ave.
Restaurant owner Mark Domitrovich says the three victims -- two men and one woman -- were his employees. According to Domitrovich, their injuries do not appear to be life-threatening.
Domitrovich says the employees saw the suspects trying to break into a car. They apparently followed and were all shot.
"There were five guys breaking into a car across the alley. And it happened to be one of the employees that worked here. And they went outside to find out what was going on. A bunch of people went out there. And the next thing you know shots were fired and three people got hit," said Domitrovich.
"We heard some noises and we heard two gun shots, a pause and three more," said Lauren Wickel.
No arrests have been made.