Howard League for Penal Reform chief executive Frances Crook says the Home Secretary missed an opportunity with her speech at the Police Federation annual conference.
She told ITV News: "I think the Home Secretary's speech was a bit of a missed opportunity. She gave them a sop of mandatory life sentences for the killing of a police officer, which I think is a nonsense because people who kill a police officer will spend almost all their life in prison anyway.
At the same time, she spent a large part of her speech criticising them for all sorts of failures, which is a missed opportunity to give them some encouragement for a complicated job they do, dealing with a whole range of social, economic...mental health issues, as well as crime fighting.
"And I think she failed to understand that."
Vice Chair of Police Federation Steve White has said the federation welcomes the announcement by the Home Secretary Theresa May that police killers are to face minimum whole-life jail terms.
Responding to Mrs May's comments that she wanted to stop officers from bringing "frivolous" law suits against the public, Mr White said: "We need to have a further conversation with her about this compensation culture she claims exists - and it doesn't."
Nurses are to join police officers sent to deal with incidents involving mentally-ill offenders under proposals unveiled by the Home Secretary today.
Speaking at the Police Federation of England and Wales' annual conference, Theresa May said one of the biggest blocks to police officers is the time taken up dealing with people with mental health problems.
Among a number of proposals for tackling this problem, she announced plans that would see nurses accompany police officers when it is likely to lead to a person being sectioned under the Mental Health Act.
This is already being done in street triage services in Leicestershire, Cleveland and Scarborough and the Government wants to roll it out across the country.
Mrs May said: "Police officers have many skills, but they are not in a position to be psychiatrists diagnosing and treating mental illness - nor are you meant to be social workers or ambulance drivers.
"You are thrust into that role because when members of the public have concerns for an individual's safety, they do not know who to call for help - except the police.
"But police officers are not doctors, and it is quite wrong that in more than a third of cases where mentally ill people are detained for their own safety, the place of safety is not a hospital but a police cell."
Jon Hassall, chairman of Lincolnshire Police Federation, asked the Home Secretary about the impact of spending cuts on resources and pensions.
He said: "Your Government uses phrases like 'we're all in this together'. That rings hollow now."
He added: "People I represent are now taking home less pay than they used to. Are you aware vast swathes of the police force don't trust you or your Government?"
Theresa May replied: "I recognise the difficulties that this has led to for some."
There was applause for the Home Secretary at the Police Federation Conference in Bournemouth as she confirms whole life terms for police killers.
But Theresa May criticised police officers for suing the public for falling over and was very clear that she doesn't want police to make frivolous claims.
She also commended the Police Federation for investigating corruption adding that is was important to the public.
The Home Secretary Theresa May has told the Police Federation Conference that she wanted to stop officers from bringing 'frivolous' law suits against the public.
"I know that the vast majority of you are dedicated public servants of the best kind" she said.
"But when a police officer sues a member of the public because they slipped on private property that is simply not the sort of attitude police officers should exhibit".
"I want to work with the Federation to make sure police officers don't make frivolous claims".
"Not least because it would be quite wrong if people become reluctant to call the police for fear of being sued".
The Home Secretary Theresa May has told the Police Federation Conference that the murder of a police officer "is an appalling crime".
She said the government would change sentencing guidelines to ensure that anyone who kills a police officer should get a life sentence without parole.
Theresa May has told the Police Federation delegates that the government wanted to support police officers.
– Theresa May, Home Secretary
Being a police officer is a tough, dangerous job. Those of us who work behind desks should never forget that you face the possibility of an encounter with lethal danger every day. You know it the moment you leave the station to do your job.
There is no more poignant reminder of the public service performed by police officers than the roll call of those who lost their lives over the last twelve months.
The Police Federation Chair Steve Williams has told the Home Secretary Theresa May that "on a daily basis our members are having to make tough decisions".
Addressing the conference Mr Williams said the federation "understood the financial realities but the police service has taken its share of pain and some would argue more than its fair share".
"But what has not helped is that times it has felt more like a punishment than an exercise in frugality" he continued.
"That what should be a cut bought about by fiscal difficulties feels like a penalty or punishment for bad conduct. Too often the behaviour of the small minority of officers is held up as that of the majority".
There have been 7 direct killings of police officers in the course of duty since 2005.
The charity the Police Roll of Honour Trust lists those killed.
- 2013 - PC Phillippa Reynolds was killed when the patrol car she was a passenger in was hit by a stolen car in Londonderry.
- 2012 - PCs Fiona Bone and Nicola Hughes were shot by Dale Cregan in Greater Manchester.
- 2012 - PC Ian Dibell was killed after he tried to wrestle a gun from an armed man.
- 2007 - PC Gary Toms from the Met Police died after suffering serious head injuries while investigating a robbery.
- 2006 - PC Joe Carroll died following a crash on the A69 after a prisoner tried to escape from his car.
- 2005 - PC Sharon Beshenivsky was shot dead during a bungled robbery in Bradford.