Just as Martin McDonagh’s “Seven Psychopaths’’ hits movie screens, Theatre on Fire and Charlestown Working Theater are offering another pungent slice of low life from the mind of McDonagh: “A Behanding in Spokane.’’

An alternate title for this darkly comic study in monomania, directed by Darren Evans, could be “One Psychopath, One Borderline Case, and Two Nervous Grifters Who Are in Waaaay Over Their Heads.’’