Hamlin

Sgt Hamlin is the first known person to take a Stalker down single handedly.

He and his squad patrolled Manchester, England and when almost all of the British resistance aircrafts were shot down the stalkers started to kill the ground forces in the city. When One Stalker ambushed his squad Sgt Hamlin ran around the back of it and concentrated fire on its power core which destroyed the Stalker.

The intel with this information was found with a dead soldier under a bridge next to Manchester Cathedral so we believe Hamlin was killed along with his men on the bridge.