Onlookers were horrified as a man armed with two kitchen knives set upon a squaddie - understood to be in full uniform - outside Brompton Barracks in Gillingham, Kent, on Tuesday evening.
Kent Police said officers were called around 6pm to reports of an assault in Sally Port Gardens.
A man, 24, was arrested on suspicion of murder within half an hour, the force said.
The suspect is reported to have left the scene on a motorcycle and at approximately 6.30pm was located and arrested in Mooring Road, Rochester.
A witness who saw the arrest told The Sun: “He was just standing there, like he knew he’d been caught.“He wasn’t resisting at all, he was fully compliant.
“He looked empty behind the eyes. It was genuinely unnerving, especially around here.
“He was wearing the same clothes he’d been wearing at the scene.”
Soldier fighting for life after frenzied knife attack outside army base as maniac, 24, arrested for attempted murder
Photos from close to the attack showed the man wearing a ski mask and a £100 Urban Outfitters NASA-branded bomber jacket.
A local added: “I’d seen him out and about on the street but I didn’t know who he is, and never got his name.
“He wouldn’t be outside often but you’d see him from time to time.”
Chilling Ring doorbell footage, which The Sun is choosing not to publish, captures a woman's screams during the 20 second attack.She can be heard yelling: "What the f*** are you doing?"
The woman then shouts "f***ing hell" before begging someone to call 999.
Neighbours had no choice but to watch the horror unravel yesterday as the knifeman used two blades to repeatedly stab the British soldier.
Further "blood-curdling" screams rang out as the victim's wife rushed out of her home in a desperate bid to pull the attacker off.
She then begged other soldiers to get out of their cars and help her stricken husband, who is understood to have been in full uniform.
The squaddie managed to get back on his feet and stagger towards his house before the attacker launched into a second savage assault.
Moments later, he ran his finger across the knife and licked it in front of shocked bystanders, a witness said.The soldier was airlifted to hospital where he remains in a critical condition, police confirmed.
The horror attack has chilling echoes of the shocking murder of Fusilier Lee Rigby more than a decade ago.However, it is not thought to be terror-related at this stage and may have been the result of a mental health episode, according to the force and Home Office.
Horrified neighbours told how the soldier was out for his regular evening walk when he was ambushed.Alex Reynolds, who lives opposite the road, told The Sun: "The first thing I heard was a piercing scream.
"When I first went down there I thought it was a scuffle between two people, but as soon as we got there we realised it was more.
"I saw a man on the floor. We stayed down there for about half an hour until they put a cordon up, nobody could really believe it had happened."
His dad Simon Reynolds added: "There was a lot of screaming and the intensity of the screaming and carrying on I could tell it must be more than a normal domestic.
“I've never heard screaming like that. It wasn't people squabbling - someone was in terrible distress. It sounded like hell.
The alleged knifeman, wearing a NASA jacket and a ski mask, pictured behind a motorcycle at the scene
A picture shared on X claimed to show cops near the scene in KentCredit: X
“There was a lot of squabbling and people moving around and then people started gathering.
"I could hear a woman shouting 'call the police'. I wasn't sure whether it was his wife.
"The police arrived, first in one car beeping their horn a lot and then another car drove round him and rushed the attacker."
While another witness said: "Blood was everywhere as I tried to apply pressure to his wounds until the police arrived.
"When the guy's wife came out and started trying to pull the guy off he didn't even try to hurt her."
Kent Police today confirmed a "number of knives" were seized from the scene, which remains behind a cordon.
Acting Chief Superintendent Richard Woolley, of Kent Police, said: "‘This was an upsetting incident for all concerned and our best wishes go to the victim, his family and those who witnessed the incident.
"Residents will experience an increased police presence in the Gillingham area and I would like to reassure everyone that officers responded quickly to take a man into custody and we do not currently believe anyone else was involved.
"The motivation for the attack is currently unknown and forms part of our ongoing enquiries, although we are exploring the possibility that it may be mental health-related.
"We are also investigating any possible links between the location and the suspect.
"There is no further information at this time to suggest there are any wider threats to the local community including members of the armed forces."
The attack was also condemned by ministers today including PM Sir Keir Starmer.
"All our thoughts are with the soldier, his family and our Armed Forces community, who serve to keep all of us safe. I wish him a swift recovery."
