A man in his 20s was killed after trying to protect an 84-year-old retired barmaid from a knifeman.
Police were called to Albany Parade at around 8pm on Friday night after a man and woman were stabbed at a kebab shop.
The woman, named locally as Betty Walsh, was rushed to hospital after being stabbed. The man tragically died at the scene.
Ms Walsh worked for many years at The Griffin pub.
Manager Gerhard Peleschka described her as a “Brentford legend”.
He said: “Betty used to work here on match days during the busiest times.
“She was here until 1978, she was the best barmaid you’d ever meet.
“She knew everyone, everyone loved her. People knew her for years and years, she’s a Brentford legend.
“What happened yesterday is just so tragic, because she is so well-known.”
He said Ms Walsh, originally from Ireland, is a mother of seven.
She is “fit as a fiddle”, he said, adding: “It just blows your mind what happened to her.”
He added the incident was unusual in a close-knit community where “everyone knows everyone”, and described it as “an absolutely safe area”.
Earlier, Ms Walsh’s grandson left a bouquet of flowers at the scene.
One of her sons, who did not give his name, arrived shortly afterwards. He declined to speak to reporters, except to say: “This is England. This is society.”
The Met said a man in his 30s was arrested on suspicion of murder and attempted murder on Saturday morning and he remains in custody at a London police station.
Police said there is no evidence linking the stabbings to terrorism and no-one else is being sought over the incident.
Inquiries are ongoing to establish if anyone involved was known to each other.
Anyone with any information has been asked to call 101 quoting the reference number 6423/12nov.