Statistically, she was just another victim of violent Britain, but the bleak irony of Pat Regan’s death will be lost on no one. The 53-year-old mother of five made it her mission to wipe guns and knives from the streets. On Sunday, she was found stabbed to death.

Mrs Regan’s campaign, which started after the fatal shooting of her own son in 2002, led to her being courted by Cabinet ministers, praised by royalty and photographed with Tony Blair.

As a leading member of Mothers Against Violence, she took her message into schools, prisons and young offenders’ institutions. She led street marches, gave interviews and held one-on-one sessions with parents.

Friends recalled tripping over boxes in her tiny flat overflowing with letters of thanks from people whose lives she had changed. The boxes were still there at 7pm on Sunday when police were called to her maisonette in a four-storey council block in Leeds.Officers found Mrs Regan dead. Her 20-year-old grandson, who has a history of mental health problems, is being held on suspicion of her murder.

Patsy McKie, a close friend, told The Times that Mrs Regan was an ordinary person who happened to do something extraordinary with her life.

Danny Regan, her youngest son, died aged 26 in 2002 when a killer with a pump-action shotgun burst into his home in St Helens, Merseyside, and shot him in the chest. His death, which remains unsolved, bore all the hallmarks of an underworld hit.

Mrs Regan would speak later of the mourning that knew no closure. With the murder of a child, she said, the pain never went away. She used it to drive her forward. A group of mothers in Manchester had formed Mothers Against Violence to highlight the growing gun and knife culture. Mrs Regan offered to form a Leeds branch.

She was no saint — she had a criminal conviction — but friends say she had a burning desire to awaken society, particularly the young, to the dangers of carrying weapons. When she spoke it was always blunt and from the heart. People listened.

Tributes to Mrs Regan were paid yesterday by Leeds MPs, police officers and Jacqui Smith, the Home Secretary. Hilary Benn, the Environment Secretary and MP for Leeds Central, said that she “made a huge impression on everyone she met”. Shane Regan, her son, wept as he said: “She dedicated her life to stopping violence like this.”

Rakeem Regan, 20, was also being questioned about the stabbing of a staff member at Leeds railway station on Sunday.

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