Letwan Taylor was taken into custody and evaluated at St. Bernard Hospital on Monday after Chicago police say he shot both his great-aunt and great-grandmother inside their Park Manor neighborhood home.
On Tuesday, he was charged with one felony count of first degree murder and one felony count of attempted first degree murder, both domestic-related.
The great-grandmother was identified as 88-year-old Valoria Taylor.
According to Chicago police, officers responded to a disturbance call in the 7000 block of South Prairie around 1:30 a.m. Monday.
When police arrived, they found a 39-year-old woman shot in the face in the stairwell of the two-flat home. Still alive, she was rushed to the hospital.
On the second floor, the 19-year-old man was barricaded inside the apartment. SWAT was called as police negotiated with the man for hours. He gave himself up without incident around 7:30 a.m.
When investigators entered the apartment they found a weapon and Valoria Taylor's body.
Police are still investigating the circumstances surrounding the shooting, but neighbors say Taylor's great-grandson lived with her and may have had mental health issues.
The second woman shot is expected to recover.