Sex, truth and transgression
By and large, media coverage of Brandon Teena's murder portrays it as the inevitable consequence of sexual deviance and deceit. Newspaper headlines routinely address Brandon Teena's ambiguous gender identity as the true 'cause' of his murder. Such headlines include: "Death of a deceiver"; "Deadly Deception: Teena Brandon's Double Life May Have Led to a Triple Murder"; "Man Who Killed Cross-Dressing Rape Accuser Gets Death Penalty"; "Cross-Dresser Killed Two Weeks After Town Learned Her True Identity." These headlines mirror the sentiment of Sheriff Laux, to whom Brandon Teena issued an oral and written statement regarding his rape by John Lotter and Marvin Nissen. When asked why he didn't arrest the two suspects after Brandon's rape accusation, Laux stated that he did not trust Brandon because she had lied about her gender. 
Media portrayals of Brandon Teena's behavior as 'deceitful' typically equate gender identity with biological sex and genitalia, such that any expression of gender identity that does not correlate to biological sex is construed as trickery or cunning. Journalist Eric Konigsberg asserts journalistic authority over Brandon Teena by evoking the 'truth' of her dead body in the opening sentence of his article. In his assessment, "Teena Renee Brandon's mystery was over the moment her body was discovered, facedown on a bed in a farmhouse in Humboldt, Nebraska."  Konigsberg's account persistently blames Brandon for deceit and, implicitly, for his own death. He uses judgment-laden terms to evoke the "double life of Teena Brandon: uneasy tomboy by day, cool lady-killer by night. Teena didn't seem to have trouble finding new people to con, new women to woo." 
Given the prevalence of public anxieties to know the 'truth' about one's sex, it is important to inquire into the stakes of a discourse that posits sexual 'deceit' as the cause of, and justification for, execution. The notion that there might be a truth of sex is produced by "regulatory practices"  underlying the binary construction of sexual difference, through which masculinity and femininity are constituted as the only possible avenues for gender identification. As Judith Butler notes,
The cultural matrix through which gender identity has become intelligible requires that certain kinds of "identities" cannot exist—that is, those in which gender does not follow from sex and those in which practices of desire do not "follow" from either sex or gender. "Follow" in this context is a political relation of entailment instituted by the cultural laws that establish and regulate the shape and meaning of sexuality. 
This matrix produces non-binary sexual identification as invisible, impossible, deviant, and/or deceitful. When medical practitioners assign a gender to intersexed infants, for example, their decisions ensure that the gender expressions of such children will conform to the 'truths' of their genitalia. Similarly, sex education that construes the female body as rapeable helps to construct 'true' masculinity as aggressively sexual, and to ensure that 'good' girls will conform to the passive sexual practices associated with 'true' femininity. The net effect of these regulatory discourses is to prohibit and punish any gender identifications that upset the sexual status quo.
Transgendered identity is especially perceived as a threat to binary sexual difference. Many theorists regard transgenderism as a challenge to the purported truths of sexual identity. For example, Marjorie Garber interprets the cross-dresser as a transgressive embodiment of ambiguity, or a "figure that disrupts."  Similarly, Judith Butler maintains that cross-dressing "provides critical opportunities to expose the limits and regulatory aims of the [binary] matrix of intelligibility, and to open up [...] rival and subversive matrices of gender disorder." 
Although it is crucial to imagine the subversive potential of 'gender disorder,' it is also important to recall that with such potential come certain limits. As Butler acknowledges with respect to drag, the practice of parodying dominant gender norms does not necessarily displace them.  While some people celebrate the disruptive potential of transgenderism, others respond to transgendered individuals with a hatred that manifests itself as an obsessive will to truth and power. 
In Boys Don't Cry, the will to power is most brutally portrayed in an episode of forced bodily exposure. In this filmic scene, Lotter and Nissen expose Brandon's body for everyone to see. The act of revealing produces in the perpetrators an effect of absolute power and orgasmic pleasure. Later, when Lotter and Nissen beat and rape Brandon, they effectively carve their initials onto the surface of his body. Their actions reassert male dominance over a woman (or, in their words, a "lying bitch"), and violently engrave her body with their power and authority as a theoria of knowers and truth-tellers. Lotter and Nissen delight in forcefully exposing Brandon Teena's genitals, which they equate with her 'true' gender identity. Through this incident, it becomes possible to read Brandon Teena's murder as the acting-out of hatred for a woman who rejects binary sexual difference. Brandon's genital exposure involves a gruesome performance of patriarchal, heterosexist power that brands enforceable limits and truths about gender identity onto the female body. These limits are enforceable in the sense that they can be upheld at whim, at the very moment that someone decides to punish perceived transgression of the sexual status quo.