Sally Evans, the mother of the British man killed fighting for al-Shabaab in Kenya said a journalist first broke the news that her son Thomas was dead.
His brother Michael was shocked to find a picture of the al-Shabaab fighter's body when he searched on Twitter for news.
"We remember him as being my brother, your son," he told the BBC. "But to everyone else he's just a terrorist."
25-year-old Evans, a Muslim convert, was killed on Sunday when al-Shabaab fighters attacked a military base in the north of Kenya, according to officials.
Militants armed with AK47s and grenades stormed the base in Lamu County, near the Somali border, and then targeted a nearby village.
Eleven gunmen were killed in total and two Kenyan soldiers also died.
Evans, from Buckinghamshire, said she would remember her son as "the little boy who had a bright future before he went down the path he went down".
She said he had met "some people with some very twisted, warped ideas of Islam" in the local area to begin with, and was later influenced by online material.
"I'm very angry that they were prepared to put my son on the line but they are still here," she said. "They are not brave enough to go out there themselves."
In 2011, Evans told his family he was travelling to Egypt. He converted to Islam and changed his name to Abdul Hakim, contacting his family in 2012 to say he had travelled to Somalia to join the militant group al-Shabaab.
His mother attacked British authorities for not doing enough to prevent her son from travelling to Egypt.
"If they had suspicions, why didn't they involve me?
"We could have worked together to save him and I wouldn't be in this situation now," she said.
"They should have taken his passport. If I'd have known, I would have taken his passport but when they let him fly to Egypt, I thought there was nothing to worry about."
"He did say if the worst thing happened, I wasn't to cry because he would be going to paradise, but somehow I cannot celebrate that."