Police continue to appeal for information following a fatal shooting in Barking.
The murder investigation was launched after police were called at 19:09hrs on Sunday, 19 March to reports of a shooting in St Ann's, IG11.
Local officers, firearms officers and the London Ambulance Service (LAS) attended the scene and found a man, believed to be aged 18, with a gunshot wound to the head.
He was taken by the LAS to an east London hospital where he was pronounced dead at 22:25 hours.
Next of kin have been informed.
A post-mortem examination is scheduled to take place at 11:00hrs on Tuesday, 21 March at Queens Hospital Mortuary.
Formal identification awaits.
Detectives from the Homicide and Major Crime Command are investigating. Detective Chief Inspector Jamie Piscopo leads the investigation and said:
"I am appealing for anyone who was in the area of St Ann's at around the time of the murder and who saw anything suspicious to contact police.
"My team continue to work to establish the series of events which led to this murder and, at this early stage, retain an open mind as to the motive."
A 20-year-old man has been arrested in connection with the murder and is currently in custody at an east London police station.
Anyone who witnessed the incident or has any information is asked to contact the incident room on 020 8345 3715 or call Crimestoppers, anonymously, on 0800 555 111.