The Florida rapper also posted surveillance images of the suspect to his Instagram account.
T-Pain has launched a Twitter appeal to help find the man suspected of murdering his niece.
23-year-old Javona Glover was fatally stabbed in a branch of the Walgreens pharmacy chain in Tallahassee, Florida on Tuesday morning (August 30).
T-Pain later shared a picture of his niece to Instagram.
The Tallahassee Police Department has identified 25-year-old Tavon Q. Jackson as the suspect, reports WCTV. CCTV footage has been released showing Jackson at the time of the murder. T-Pain also posted surveillance images of the suspect to his Instagram account.
T-Pain has asked reporters to leave his family to grieve.