Pete Martell - Johnson Family - Leo Johnson

Leo Johnson, played by Eric Da Re, is a trucker who also moonlights as Twin Peaks' primary source of narcotics (which he obtains from the Renault Brothers and traffics over the Canadian/US border for distribution in Twin Peaks). Because of his criminal versatility, Sheriff Truman has never been able to obtain any evidence of his criminal dealings. Leo is married to Shelly Johnson, one of the waitresses at the town diner. Due to his volatile temper, he regularly beats her for both real and imagined transgressions, ranging from her infidelity with high school football player Bobby Briggs to his dissatisfaction with the way she washes the kitchen floor.

In the course of the series, cumulative evidence leads to Leo becoming one of the primary suspects in the murder of Laura Palmer. As it turns out, Leo was simply present on the night Laura was murdered by Killer Bob. While under investigation for the Palmer murder, Leo is hired for his criminal skills by Ben Horne, who charges him with burning down the Packard Saw Mill with his business rival Catherine Martell inside so that Horne can simultaneously kill his competition and destroy the only obstacle to his obtaining the valuable Mill land. Leo decides to use the situation to solve his own marital discord, abducting Shelly and tying her up inside the mill shortly before setting fire to it with a time bomb. Catherine foils his plans by freeing Shelly and helping her escape the mill. When Leo returns home after setting fire to the mill, he discovers Bobby in his house looking for Shelly. Leo tries to kill him with an axe, but is shot by Hank Jennings, who was hired by Ben Horne to kill Leo in order to cover his own tracks.

Leo spends most of the second season in a vegetative state, cared for by Shelly and Bobby, who agree to take him in as part of a scheme to commit insurance fraud. The plan backfires, however, when it turns out that Leo's home care is far more expensive than they had anticipated, and the pair are left destitute. To vent their frustration, they take to abusing Leo whilst simultaneously flaunting their relationship in front of him.

Near the end of the season, Leo regains some of his cognitive abilities and attacks Shelly and Bobby. Wounded during the course of a struggle, he staggers into the woods, where he is abducted by escaped mental patient (and former FBI agent) Windom Earle. Earle enslaves the barely coherent Leo by fitting him with a shock collar and forcing him into submission. Leo spends the remainder of the series as a semi-mute drone, serving Windom Earle as his henchman. In the third to last episode, Leo seems to regain some more functioning ability, as he frees another one of Earle's captives, Major Garland Briggs, believing Shelly's life to be in danger after Earle posts a photo of her on his cabin wall. (Ironically, this gives the impression that Leo truly did love Shelly-in his own cruel way.) In the series finale, Earle leaves Leo for dead, rigging a cage of tarantulas above Leo's head, with a string affixed between Leo's teeth; if Leo lets go of the string, the cage will drop on his face, releasing the agitated tarantulas. His fate is never revealed, though it is rumored that he might have had the cage drop during the third season.