The gay panic defense is a legal defense against charges of assault or murder. A defendant using the gay panic defense claims that he or she acted in a state of violent temporary insanity because of a little-known psychiatric condition called homosexual panic.Trans panic is a similar defense applied towards cases where the victim is a transgender or intersex person. This defense often fails, and has been ruled inadmissable in many jurisdictions because of a complete lack of scientific research to support it.

In the gay panic defense, the defendant claims that they have been the object of homosexual romantic or sexual advances. The defendant finds the advances so offensive and frightening that it brings on a psychotic state characterized by unusual violence.

Guidance given to counsel by the Crown Prosecution Service of England and Wales states: "The fact that the victim made a sexual advance on the defendant does not, of itself, automatically provide the defendant with a defence of self-defence for the actions that they then take." In the UK it has been known for decades as the "Portsmouth defence" or the "guardsman's defence" (the latter term was used in an episode of Rumpole of the Bailey made in 1980). In Australia, it is known as the homosexual advance defence (HAD).

Matthew Wayne Shepard (December 1, 1976 – October 12, 1998) was a student at the University of Wyoming who was tortured and murdered near Laramie, Wyoming, US, in October 1998. He was attacked on the night of October 6–7, and died at Poudre Valley Hospital in Fort Collins, Colorado, on October 12 from severe head injuries.

During a pre-trial hearing, a Laramie police officer testified that the violence against Shepard was due to how the attacker "[felt] about gays," per an interview of the attacker's girlfriend who said she received that explanation. Shepard's murder brought national and international attention to the contention of hate crime legislation at the state and federal levels.

In 2009, his mother Judy Shepard authored a book The Meaning of Matthew: My Son's Murder in Laramie, and a World Transformed. On October 22, 2009, the United States Congress passed the Matthew Shepard and James Byrd, Jr. Hate Crimes Prevention Act (Matthew Shepard Act for short), and on October 28, 2009, President Barack Obama signed the legislation into law.

Kevin Grant Hague (born 18 March 1960) is a current New Zealand MP representing the Green Party who was first elected to parliament in 2008.

As of 2009^[update] he is the Green Party spokesperson on Health and Wellbeing, Commerce, Small Business, Tourism, Biosecurity & Customs, Cycling & Active Transport, Sport & Recreation, Rainbow Issues, and Rural Affairs; and associate spokesperson on Community Economic Development, Gambling, and Community & Voluntary Sector.

Prior to his election he was the Chief Executive of the West Coast District Health Board. He is also an author, long time gay rights activist and a former executive director of the New Zealand AIDS Foundation.

Hague has been an activist for a number of causes. In the 1980s he was heavily involved in the campaign against sporting contacts with apartheid South Africa. In 1989 he co-authored Honouring the Treaty: an introduction for Pakeha to the Treaty of Waitangi. Hague is openly gay and in 1988 began work as a research officer for the New Zealand AIDS Foundation, which provides education on HIV/AIDS issues and advocacy and support for those with HIV and AIDS. From 1998 to 2003 he was the Foundation's executive director. He has represented New Zealand at United Nations, UNESCO and Commonwealth conferences on apartheid and on AIDS. He has also campaigned on behalf of mountain bikers.