A man who was blinded when his former partner poured acid over him while he slept is suing the police force he claims could have prevented the attack.
Daniel Rotariu was attacked by Katie Leong in Leicester in 2016. She is serving a life term after being found guilty of attempted murder.
The Independent Office for Police Conduct (IOPC) said Leicestershire Police was warned about her plans.
The force said it "cannot comment at this stage" on the legal proceedings.
Mr Rotariu is seeking £12,000 to support his legal bid.
The 33-year-old was in a medically induced coma for six weeks after Leong poured 96% pure sulphuric acid over him.
As well as leaving him blind, the attack left him with severe scars to his arms, head, legs and torso and needing several operations.
Leong's trial at Leicester Crown Court in March 2017 heard how she had become fixated with carrying out an acid attack.
Her ex-partner Mark Cummings, who was on trial alongside her, said he raised concerns to his probation officer about why she wanted to buy the acid.
Leong was sentenced to serve a minimum of 17 years, while Mr Cummings was cleared of attempted murder by a jury.
An investigation by the IOPC, found police had received reports months before the attack that Leong "was acquiring acid to carry out a premeditated attack on an unnamed third party", and that her former partner Mr Cummings had been in contact with her in breach of a restraining order.
Officers failed to contact Leong over the allegations, the watchdog said in its report; with two call logs "closed down inappropriately".
A police constable and a member of police staff were subject to management action over their "unsatisfactory" handling of a claim regarding the breach of Mr Cummings's restraining order.
Mr Rotariu said he would "never recover" from his injuries and needed financial help from the public to continue his legal action against Leicestershire Police.