Late Monday, the New York City Police Department released the sketch of a man suspected in the murders of a 6-year-old boy on Sunday and an 18-year-old woman on Friday in Brooklyn.
Police described the suspect on Monday as a black male between 25 and 35 years old, approximately 6 feet tall with a heavy build and last seen wearing a grey shirt.
Authorities officially drew a link between the two stabbings on Monday evening, and that detectives had "identified several common factors" between the cases.
"These factors, including the types of weapons used in the two homicides, and the close proximity of the incidents, led detectives to believe that both of these cases may be related."
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Investigators recovered what they presume was the weapon used at the scene of Sunday's attack, where Prince Joshua Avitto, 6, died from stab wounds inflicted by the unidentified assailant. Seven-year-old Mikayla Capers was also critically injured but survived the violent incident.
She remains at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.
Cops said the knife used in Sunday's attack was a "Dura Edge" knife that had not been manufactured since 2004.
The Boulevard Houses in East New York were first rocked by the stabbing death of Tanaya Copeland late last week.
At the time, police said they found her bleeding from multiple stab woulds in her torso at around 10:22 p.m. on Friday, unconscious and unresponsive. Emergency workers rushed to the Brookdale University Hospital and Medical Center, but she was pronounced dead soon after.
Police continue to ask that anyone with information about the suspect or either attack to contact Crime Stoppers at 800-577-TIPS or to submit tips online.
Follow Chester Jesus Soria on Twitter@chestersoria