A troubled mum slashed two policemen after repeatedly refusing to put down a kitchen knife.
An officer on patrol in Fairfield stopped to chat to "dishevelled" and hooded Sheena Farrell to see if she was okay.
But the 43-year-old ignored his requests to take her hands out of her pockets, before revealing a large carving knife.
Bodycam footage showed he sprayed Farrell with CS gas but she fled, so he chased after her and called for back-up.
However, when colleagues arrived she still wouldn't drop the weapon and they were forced to try and disarm her.
A sergeant repeatedly hit Farrell with his baton, but she slashed and stabbed at him as they both fell to the ground.
The mum-of-two still hadn't let go of the blade, so another officer dived on top of her and she finally released her grip.
Farrell kept saying "I'm sorry, sorry love" as the sergeant realised he had a wound on his thumb, requiring three stitches.
He then discovered a second cut to the top of his arm, which needed a solitary stitch, and his colleague's head was cut.
The first officer thought Farrell was high on drink or drugs when he spoke to her in Onslow Road at around 9pm, on December 3 last year.
Liverpool Crown Court heard a man came out of his house and said she had been walking in and out of his front garden.
On the footage the officer could be heard to say: "You keep messing with that pocket, take your hands out your pocket for me."
Farrell apologised but repeatedly said "I can't, sorry love" and when asked what was in her pocket replied: "Nothing, why?"
She gave the false name of Mary Sweeney and said her friend used to live in the man's house, before pulling out the knife.
The officer commanded "put it down" over and over, but she kept shouting "I haven't stabbed anyone" and ignored him.
He asked for colleagues with Tasers to attend as he wasn't armed with one and warned Farrell they were coming.
The sergeant shouted "put the knife on the floor and no one will hurt you", but she yelled: "No, I haven't done nothing."
Derek Jones, prosecuting, said the sergeant used his baton and there were "clearly several stabbing or slashing motions".
After they fell, he said the other officer could still see her with the knife, so "dived in on top of her to wrestle the knife off her".
He said: "We don't really know how it happened, but he suffered a 5cm gash or cut to his forehead, which required glueing."
When interviewed, Farrell said she always carried a knife for protection, but today shouted from the dock this was false.
Farrell accepted she didn't want to be arrested and slashed her victims to try and get away, but again apologised.
She was originally charged with wounding the sergeant with intent, but admitted simple wounding against both officers.
Farrell, of no fixed address, who has two previous convictions for seven offences, also admitted having a knife in public.
Her criminal record includes two assaults on police in 1995 and criminal damage and battery in 1999.
Mr Jones said both victims told the court they were family men only doing their job and trying to serve the public.
He said: "Family members of police officers are always worried when they are out on duty and this will add to their worry."
The judge, Recorder Ahmed Nadim, said: "What started off being a welfare enquiry ended up being a most tragic incident."
Rebecca Smith, defending, accepted it was "unsavoury and unpleasant", but said Farrell had been out of trouble for 20 years.
She said her client was released from a mental health unit 12 months previously, but her condition had deteriorated so badly her social worker had asked for a review.
The lawyer said Farrell had been on medication for schizophrenia since she was 23 and her children were taken off her because of her mental health and "drug misuse".
Ms Smith said that led to a "downward spiral", but added: "She tells me she has for a long period of time tried to remain drug free."
The lawyer said it was "at a time of a crisis point in her life" and Farrell was now taking her medication and getting help in jail.
Recorder Nadim said the incident illustrated how dangerous carrying a knife in public was and that Farrell left the officers with "no choice".
The judge said: "This was on your part a most grave breach of the law."
He added: "All the police officers wanted you to do was surrender the knife."
The judge jailed her for two years, to which Farrell replied: "Thank you your honour. I'm very sorry, sorry love."
