Police say Singleton was shot several times around 10:30 a.m.
Homicide Sergeant Dave Walker said the investigation shows Singleton spent the night with a woman who lives in the complex. Walker said the woman is the mother of the his child and the woman's ex-boyfriend, Hendrick, was angry that Singleton spent the night with her.
Walker said the woman and both men had a confrontation outside the apartment, in a common area outside. Walker said Hendrick shot Singleton several times with a handgun before leaving in a black and white Crown Victoria.
According to Walker, police were familiar with Hendrick and his car and gang unit officers tracked him down on East 71st Street as he went to his own apartment.
After a short foot chase, he was taken into custody.
Monday morning, Sergeant Jillian Phippen said witnesses provided valuable information that led police to the arrest.