Accidental Shooting in New Orleans - 15-Year-old Arrested

Local news reports

The NOPD arrested a 15-year-old boy accused of accidentally shooting his 11-year-old brother in the leg Thursday night. The 15-year-old will be booked on a charge of negligent injuring, said officer Frank Robertson III, spokesman for the New Orleans Police Department. 
The two brothers were playing with a loaded pistol around 7 p.m in the 2700 block of Onzaga Street. The pistol was accidentally fired, shooting the 11-year-old, Robertson said. The child has been taken to the hospital, where he is listed in stable condition.

Don't you find it odd that no adult is held responsible?