PHOENIX -- Police say 18-year-old Vincent Quimayousie is the man who shot and killed a 16-year-old boy in a Phoenix park Thursday evening.
It happened just after 7:30 p.m. at Marivue Park, which is located at 55th Avenue and Osborn Road.
According to Officer James Holmes, witnesses told investigators that Quimayousie committed one armed robbery in the area and was in the process of a second when Andrew Murphy tried to intervene.
"The 16-year-old was shot protecting his little sister," Holmes said Friday morning.
The suspect fled the scene, but there were several people in the park at the time of the shooting and they were able to give police valuable information.
Based on what those witnesses told them, officers set up a larger perimeter and caught up with the suspect about a block away a short time later.
In addition to Murphy, Holmes said there were three other victims -- a 16-year-old Hispanic male, a 14-year-old black female and a 28-year-old Hispanic male. Not one of them was injured.
"This is tragic all the way around," Holmes said.
Detectives are looking into the suspect's actions leading up to the first armed robbery.
Quimayousie is being held on suspicion of first-degree murder, two counts of armed robbery and one count of aggravated assault.
Police are asking anyone who may have had contact with Quimayousie, or who may have information relative to this investigation to please call the Phoenix Police Violent Crimes Bureau at 602-262-6141 or Silent Witness at 480-948-6377.