Ryan Clay, 18, and Sabrina Nino, 17, were arrested Monday afternoon in connection with the shootings in the 1700 block of West Elm Street in Denison at about 11 p..m. Sunday, Denison police Lt. Mike Eppler told KWTX.
The 5-year-old was taken to a Denison hospital, where he later died. The older child was taken by helicopter to a Dallas-area hospital, police told KXII.
Police told KWTX that multiple rounds were fired into the home and that the boys were hit while inside.
"Right at this point, we don't know if it was a vehicle that went by or if it was somebody on foot, that much we just don't know just yet," Eppler told KWTX.
A witnesses told the television stations they heard seven to 10 gunshots.
Judy Wiley, 817-390-7843; @judygwiley