A man has been jailed for at least 22 years for murdering a woman he visited for sex and setting fire to her flat.
Neil McMillan, 42, who was convicted at Lewes Crown Court, applied "unremitting pressure" to Andrea Waddell's neck at her Brighton home in October last year.
The court heard he then went home to shower and wash his clothes in an attempt to cover his tracks.
Ms Waddell, who was born male but had undergone gender reassignment surgery, had been working as a prostitute.
Addressing McMillan, of Bennett Road, Brighton, after the verdict, Judge Michael Lawson QC said: "What you did that night brought to an end a life which in many views was one of relentless difficulty faced with extreme courage.
"The person you killed was a person who always sought to overcome difficulties.
"On the other hand, faced with a difficulty in that flat, whatever that was, you chose to take it out on her.
"You strangled her, with relentless pressure for over 20 seconds. There was the distinction between you and her."
And he added: "Once you lost control, for whatever reason and which cannot be regarded as justified, you formed the intention to destroy her, to kill her."
McMillan had denied murder, but the judge told McMillan his actions were not an accident, and that he crushed her neck until she was dead, before setting fire to the flat in order to remove all traces of his presence there.
After the hearing, Ms Waddell's family, who live in Reading, Berkshire, where Ms Waddell grew up, issued a statement which said the verdict could not take away their "terrible sense of loss and pain".
But they said: "As a family, we can now remember Andrea, her passions and the causes she fought for during her life, knowing that the person who callously extinguished that life is behind bars."
They added they hoped everyone who had read about Ms Waddell would be inspired "to live their lives true to themselves and not to judge other people for their differences".
Det Ch Insp Adam Hibbert said McMillan brutally killed Ms Waddell, then tried to cover his tracks, and had later given interviews that had been exposed as devious and deceitful.
"Due to the nature of Andrea's work, people were understandably reluctant to come forward to speak to police but they bravely did so," he added.
He said without support from the local lesbian, gay, bisexual and transgender and sex worker communities, Andrea and her family would not have received the justice they deserved.
During the trial, jurors were asked to consider whether McMillan killed her after discovering she was transgender, or because she was unable to perform sexually for him because of physical ailments after illnesses including fibromyalgia.
The court heard that McMillan, a satellite TV installer, strangled Ms Waddell while in a "worked-up and angry mood".