The Whip Fist, Shield, and optional Thermal Vision are required. At the start, when you need to collect samples, just run around and collect them. When the Boss comes in, just Whip Fist him. Note: Do not Whip Fist him while he has the electrified Billy club (police stick) or else he will shock you and take away health. When he is shooting you, before he fires he will shine a laser light. Just Whip Fist him and he will take some damage. When he goes up to the roof and the Infected appear, he will come back down in a moment. Do the same thing, only you will be attacked by Infected. This is when Shield is useful. When his friends come down to shoot you, just repeat what you were doing before.