text: She stressed that to kill a police officer was "to attack the fundamental basis of our society".
  But Mrs May also said police officers must end "frivolous" accident claims and focus on raising public trust.
  Earlier the Police Federation urged her not to base legislation changes on the behaviour of a "handful of officers".
  During her address, Mrs May said suing someone after slipping on their property was "not the sort of attitude" officers should exhibit.
  Her comments come after it emerged recently that one police officer, PC Kelly Jones, had taken legal action after tripping on a kerb at a Norfolk petrol station in August.
  Mrs May also revealed plans to allow police to take over shoplifting prosecutions where goods taken were worth less than Â£200.
  Unveiling plans for a change in legislation at the Police Federation conference in Bournemouth, Mrs May announced the government proposal that the minimum term for killing an officer should be increased to life without parole.
  The current minimum sentence for a police murder is 30 years.
  By Danny ShawBBC home affairs correspondent
  Theresa May's whole life tariff for police murderers is being welcomed by rank-and-file officers - but it's unlikely to quell the anger felt by Police Federation members about the government's programme of cuts and reforms to the service.
  High on their list of concerns is an idea, currently the subject of negotiation, which would allow chief constables to make police compulsorily redundant.
  Officers say chiefs could get rid of officers they don't like or those approaching pension age - and with no industrial rights there'd be nothing police could do about it.
  A final decision on whether the home secretary will go ahead is expected in the summer. The federation would no doubt toast Mrs May if she abandoned the whole idea.
  The home secretary told rank-and-file officers the murder of a police officer was "a particularly appalling crime".
  "We ask police officers to keep us safe by confronting and stopping violent criminals for us," she said.
  "And sometimes you are targeted by criminals because of what you represent."
  She added: "We are clear - life should mean life for anyone convicted of killing a police officer."
  The Criminal Justice Act 2003 permits Justice Secretary Chris Grayling - following consultation with the Sentencing Council - to make an order to change starting points for sentences.
  In this instance, it enables him to change the starting point from 30 years to a whole life order, meaning offenders could not be released other than at the discretion of the secretary of state on compassionate grounds - for example, if they are terminally ill or seriously incapacitated.
  The Sentencing Council, the official body that oversees sentencing in England and Wales, issues guidelines for judges and magistrates to work to for all offences other than murder.
  A spokesman said: "Introducing whole life tariffs for those who murder police officers would involve changes to the law, which is a matter for Parliament, rather than the Sentencing Council."
  But he confirmed that the government had a duty to consult with the council before new legislation could be brought in.
  The Sentencing Council says that, as things stand, whole life orders can be imposed in murder cases "if the court decides that the offence is so serious that the offender should spend the rest of their life in prison".
  There are currently 47 prisoners in England and Wales who have been given whole life tariffs, including Rosemary West and "Yorkshire Ripper" Peter Sutcliffe.
  The home secretary, who faced a question and answer session after her speech, was heckled at last year's conference after she told officers to "stop pretending" they were being singled out and would "have to make their share" of public spending cuts.
  Police Federation chairman Steve Williams, who had earlier welcomed Mrs May's sentencing plan, told her morale was low as a result of the government's programme of cuts and reforms.
  Speaking at the conference, he urged the home secretary not to "hang your reforms on the reprehensible behaviour of a handful of officers".
  The biggest applause came when he called for the government to abandon plans for compulsory severance, which are currently subject to negotiation.
  Chief Inspector of Constabulary Tom Winsor, who is behind hotly debated changes such as fast-track recruitment and lower annual pay for new constables, was also due to address officers.
  On Tuesday, shadow home secretary Yvette Cooper told the three-day conference that government plans to withdraw from the European Arrest Warrant agreement would make it harder to catch criminals who went on the run abroad.
target: Criminals who kill police officers in England and Wales will face compulsory whole life sentences, Home Secretary Theresa May has announced.