Len founded his own nest consisting of at least three members, including Starr, whom Len was responsible for turning. Len developed a philosophy of feeding from the whole of the victim, instead of just drinking the blood, a belief passed onto his followers.
Eventually, Len developed a conscience and fled from the nest, leaving Starr as the de facto ruler in his stead. Len went on to become the Sheriff of Hibbing, Minnesota.
In 2014, Len set up a sheriff's retreat and invited other sheriffs to attend. This led his face to appear on a newspaper, and enable Starr to discover where he was. Starr, joined by two of their nest members, went to Hibbing and began killing individuals. This led Sheriff Jody Mills to contact Sam and Dean for help.
As the corpses caused a disruption at the retreat, Len soon discovered that his former protege was responsible and decided to confront her. Sam, Dean, Jody and Donna Hanscum suspected Len as the murderer, but as they stalked him, they found themselves captured by Starr and her companions.
Starr confronted Len at the barn where she was holding the four hostages. She asked Len to return to them and prove himself by killing the hostages. Len refused, and Starr decapitated him as punishment.
Unfortunately for Starr, the hostages managed to break free of their bounds and attack the vampires. The three vampires were subsequently killed, and the nest was presumably destroyed afterwards.