After bringing Jill to the hospital as Carlos, you'll walk around an infected building with lots of zombies around every corner in Resident Evil 3: Remake. Eventually you have the option of upgrading your assault rifle with a tactical grip, but that's a bit out of the way.
You have the option of finding him when you explore the second floor of the hospital, shortly after you attempt to enter the room where Bard is safely. Go left in the hallway to face several zombies in the emergency entrance. Take them out, then continue to the left, then to the right where there is a staircase. A body will fall from the second floor, but it is neither alive nor undead, so you can walk past it to get to the next flight unscathed.
When you're on the second floor, head to the rooftop and walk around the area. Continue straight on from where you come out, then turn right. You should see a partially broken window with duct tape around it. When you approach the window, you are asked to exit. Do this and you'll land on the first floor, but outside, in the courtyard. To the left of where you landed is a small pot. Approach, and the tactical grip is inside.
There are plenty of other hidden objects scattered all over Resident Evi 3: Remake. Make sure to watch them and keep your eyes open when you are in the hospital.
