During the hostage scene at the school one of the NYPD's ESU (Emergency Services Unit) snipers is holding his rifle in a completely incorrect manner (the ESU is the NYPD's SWAT unit). He has the stock resting on his left shoulder, indicating he is left-handed, yet has his right hand on the trigger. A person who is a skilled marksmen, especially a professional sharpshooter like a SWAT sniper, always shoots on their dominant side. A left-handed person would hold the stock of a rifle on their left shoulder and use their right hand to hold the forward grip and their left hand to pull the trigger. Plus the rifle is clearly designed for a right-handed shooter as the action opens from the right, a left-handed SWAT sniper would always use a rifle designed for a left-handed shooter.
Alejandro says he came to in an empty apartment, but two seconds later says he as left for dead on the sidewalk.