He was a resident of Gunnison, Colorado who, in 2004, became involved in the Xenomorph outbreak that ultimately led to the destruction of the town.
Tim was a good father and a loving husband. He was killed when a Xenomorph broke into his house. He died attempting to hold the creature off so that his wife Kelly and his daughter Molly could escape.
The creature was killed later by the Predator, who then dissolved it and his body. His family survived the disaster.