A 13-year-old boy is in custody after a 15-year-old boy was shot in the head in Eastchester on Monday.   Police sources say it appears that the 15-year-old shot himself in the head and remains in the hospital right fighting for his life. The 13-year-old boy is in police custody and has been charged with criminal possession of a weapon and reckless endangerment. It's unclear the connection the 13-year-old had with the 15-year-old or why he's getting charged. According to police, the incident happened around 3 p.m. Police say they arrived at 3475 Bivona St., and that's where they found the 15-year-old with a gunshot wound to the head. The 15-year-old was rushed to the hospital, where he remains in critical but stable condition. As of right now there are more questions than answers, and a lot to piece together here. It's unclear how the 15-year-old got the gun, or who it belonged to and why that 13-year-old is getting charged.