After seemingly ignoring repeated orders to put the blade down, she was held at gunpoint before collapsing to the floor when one officer fired his Taser at her chest.
She was then dragged to her feet, handcuffed and charged with criminal trespass and obstructing an officer last Friday.
Relatives of the pensioner, who comes from Syria, said she had been cutting leaves to eat in a salad.
Police chief Josh Etheridge insisted she had posed a threat and he had no choice but to deploy the weapon in Georgia.
United Sates In a video statement, he said: “An 87-year-old woman with a knife still has the ability to hurt an officer. She came walking towards the officer.
“After multiple commands, he told her to stop several times. She continued walking at which time we deployed the Taser.”
Mr Etheridge claimed he pulled out his pocket knife and threw it on the ground to demonstrate.
He said: “I threw my knife down on the ground, trying to make her understand what we wanted her to do. There was no anger, there was no malice in this.
“In my opinion, it was the lowest use of force we could have used to simply stop that threat at the time.”
Mr Etheridge responded with the other officers after a member of the public called 911 to report that a woman was walking around with a knife and a bag cutting down vegetation.
But Ms Al-Bishara’s angry family said the officers should have shown more patience.
Her great-nephew Solomon Douhne said: “If three police officers couldn’t handle an 87-year-old woman, you might want to consider hanging up your badge.”
Family members said she spent about two hours at Murray County jail in Georgia before being released the same day and that she still has trouble sleeping and is nervous about going outside.
Her grandson, 24-year-old medical student Timothy Douhne, called the incident “ridiculous”.
He said: “She told us she was smiling at them to tell them that she wasn’t a threat and she was trying to get closer to them to communicate with them and that’s when they Tasered her.”
Martha Douhne, a great-granddaughter, said she is still suffering after the distressing drama.
Martha said: “She is still repeating the incident over in her mind and telling us she didn’t mean for this to happen and apologising that she didn’t want to bring this on us. She is having trouble sleeping and is stressed.” Police chief Etheridge said: “I felt like everything was handled by the protocol.”
He added: “Of course, we will still be reviewing this to see if there is anything we could have done differently, anything we could have done better.”