By Alison Holt
BBC News social affairs correspondent
Mr Martin's attackers were called "a pack of animals" in court
Brent Martin was, according to his family and friends, a caring and trusting man.
Even when the 23-year-old - who had learning difficulties - was being subjected to an onslaught of violence, Newcastle Crown Court was told he did not lift an aggressive finger to his attackers.
The two teenagers - one aged 16, the other 17 - and a 21-year-old man who killed him have been warned they face a mandatory life sentence.
Mr Martin had spent nearly a decade in psychiatric hospitals and had only been back with his mother for two months when he was set upon while waiting at a bus stop.
He was vulnerable and the court was told the young men convicted of his murder punched, kicked and stamped on him for their own sport.
One of these youths told others: "I am not going down for a muppet."
This was, according to campaigners, a clear case of someone being picked on because of their disabilities.
Disability Now, the magazine covering disability issues, has put together a dossier of what it believes are disability hate crimes.
Disabled people targeted
Over two years it identified fifty-one cases of people with a wide range of disabilities being attacked. Detailed in this dossier are some truly horrific attacks:
- In Cornwall in 2006, Steven Hoskin, who had learning disabilities, was murdered by people he thought were his friends. He was led around on a dog's lead and then made to hang from a viaduct by his fingertips. He fell to his death when they stamped on his hands.
- In the Forest of Dean a few months later, Kevin Davies who had epilepsy and learning difficulties died after being tortured and kept in a shed. His tormentors were jailed for unlawful detention.
- And in April of last year, Colin Greenwood who was blind, was kicked to death by two teenagers in Sheffield. He told the woman who went to help him he had stopped using his white stick because it attracted attention and he'd been attacked before.
Katharine Quarmby, news editor at Disability Now, was shocked by what she found: "I think it tells us that disabled people are targeted by a certain number of people in the population and they are seen as easy targets because of their disabilities.
"We need to increase the reporting of (these) crimes and we need the criminal justice system to look at disability hate crime far more seriously, to investigate it and prosecute it with far more vigour."
Kevin Davies was locked in a shed by his tormentors
If an offence is labelled as a disability hate crime then the courts can impose tougher sentences, but campaigners say very few of these attacks were identified in that way.
The Equality and Human Rights Commission (EHRC) believes the attacks in this dossier are the tip of the iceberg. It is planning to investigate the matter further.
Neil Crowther, from the EHRC, says they may be able to use some of their legal powers to ensure much more is done to combat crimes targeting people with disabilities.
"We need to understand much more about why this is happening, why cases are not being reported, why cases are not being determined as disability hate crimes and then make a decision based on that," says Mr Crowther.