Shocking footage shows the moment a dog with ominous history attacks a woman and her pup

New York's most notorious killer dog has struck again - a year after its owner promised to put it down.

Syko the blond Golden Shepherd mauled a series of small dogs and left one dead last summer outside La Librairie des Enfants French bookshop in the Upper East Side.

At the time, owner Lynda Hudson, 58, bowed to local pressure and said she would both have the dog euthanized and move her bookstore across town to a new site in the West Village.

But the Beast of the Upper East was filmed in another attack on Friday morning, leaving one elderly walker lying flat on the sidewalk and clutching her terrified spaniel as Syko's handler dragged him away.

'As the woman walked up the block, the dogs jumped out of the car and attacked her dog and she was knocked to the ground,' a horrified neighbor told Dailymail.com 'The husband proceeded to hit his dogs and then drove off.'

An elderly woman lays on the sidewalk desperately clutching her spaniel as Syko and his sibling are dragged away from their targets

'Syko' - second from left and pictured with his parents and siblings - mauled several smaller pups outside the quaint French bookstore La Librairie des Enfants on the Upper East Side

Syko was living with at least two of its German Shepherd siblings when it began attacking smaller animals in May last year.

Psychologist Julia Schafer was walking out of her building when Syko and his two siblings grabbed her small Collie mix Tarsilla on May 3.

'The white one bit her and held onto her,' Schafer told the NY Times.

Hudson agreed to pay the $850 vet's bill, but it was just four days later that local tech engineer Laurie Davis found herself 'screaming at the top of her lungs' as the dogs launched themselves on her small white Cavachon named Chloe.

'My friend and I were coming back from Central Park with our dogs ... next thing I know, this white dog has Chloe in its mouth,' she said.

While Syko was busying himself with Chloe, his two siblings turned their attention to the small Maltipoo belonging to Davis's friend, biting little Muppet in the face.

Chloe survived but required emergency surgery and was in critical care for nearly three days, according to Davis.

She said one neighbor from her building had 'got a wet towel and put pressure on her wound which is probably what saved her life.'

But it was August before matters came to a head when Syko was triggered by a seven-pound toy poodle called Baby who walked past his door.

Personal trainer Akiba Tripp with her seven-pound toy poodle Baby who was killed by Syko near the bookstore when the owner suddenly opened the door

Psychologist Julia Schafer, another Upper East Side local, said that she was walking out of her building with her small collie mix Tarsila on May 3 last year when disaster struck 

Chloe and her owner Laurie Davis following Syko's brutal attack on the small Cavachon in early May last year. Davis took Hudson to small claims court over the $6,000 vet bill that came as the result of lifesaving measures for Chloe

Owner Akiba Tripp said the German Shepherd grabbed her little dog 'within his mouth,' sank his teeth in, and broke her spine after Hudson had opened the door to the shop and walked out with Syko.

The personal trainer said people from neighboring bars ran over and tried to drag the dogs apart on the blood-splattered sidewalk. But Baby couldn't move because she was paralyzed from the attack.

The little poodle had to be put down but Hudson claimed that 'Syko did not kill anyone', telling the NY Post that it was Tripp who decided to 'put that dog to sleep'.

Tripp said a veterinarian insisted her dog could not be saved and tore into Hudson's account.

'For her to continue to say that, how dare she,' she spat.

'That goes to show what an evil person this woman is. The dog's spine was broken, and the doctors said we cannot do surgery.'

Davis said Hudson had blamed her 'drunk' husband for the attack, and then reneged on a promise to pay her $6,000 veterinary bills.

'She's a pathological liar,' Davis claimed. 'I have to tell you all the Upper East Side dog moms and dads up here, they don't want her here at all.

'This woman has given me such agita that I can't even begin to say.'

Syko (center) the German Shepherd is known to have attacked at least five dogs 

His handler shoved him back in the car as his latest victim lay on the ground  

One of Syko's siblings also received a stiff telling off as bystanders looked on helplessly

Eventually one came to the woman's aid and lifted the spaniel away from danger 

In an email to neighbors, Hudson apologized for Syko's behavior and said she had tried everything to tame its wild behavior.

'It's very unfortunate that this poor little dog was put to sleep and I'm so sick!' she wrote.

'I've been here for almost nine years and my adult dogs never attacked but this white German shepherd is something.

'I called my vet yesterday to ask him to put the dog to sleep and my vet refused to do it.'

But she said the vet had referred her to a clinic in Brewster, and she would keep her other dogs at home in future.

'My dogs won't be in the shop anymore but the hatred, insults name calling has to stop,' she wrote.

In April this year the bookshop shut its doors ahead of a planned relocation to the West Village.

'I'm just happy that (Hudson is) gone,' said Tripp at the time. 'I don't believe she's learned her lesson. She showed no remorse.' 

Lynda Hudson, 58, opened La Librairie des Enfants in 2016. She owns the vicious German Shepherd dog that has been mauling other animals

But just when residents thought it was safe to go back in the quarter, one filmed Syko and his sidekicks attacking the elderly lady and her spaniel.

'All the dogs were in the car with her husband,' the witness told Dailymail.com.

'And as the woman walked up the block, the dogs jumped out of the car and attacked her dog and she was knocked to the ground. The husband proceeded to hit his dogs and then drove off.'

The source said that a 'sister cafe' near the bookshop where Hudson offers child and adult conversation classes remains open for the time being.

'I don't believe she's learned her lesson,' said Tripp. 'She showed no remorse.'

Dailymail.com has reached out to Ms Hudson for comment.