More often than not family members were involved in cases of elder neglect, Dr Tamatea said.
"The caregiver may experience an increasing burden, which means sustained high levels of stress, and they may be poorly-equipped to continue to manage the situation or call for appropriate help.''
He said people who committed crimes might try to rationalise their actions by reassuring themselves they were doing nothing wrong or that their offending was somehow justifiable.
"In such situations, a person may assure themselves with biased thoughts such as victim-blaming or that aggression is normal and that others would behave similarly under the same circumstances, making future decisions to commit violence easier.
"Offenders will also engage in blaming the victim to help ease the negative emotional impact of their behaviour.''
He said if a victim was aware of the harm being caused, they might develop a sense of hopelessness if help could not be found.
"They may have that feeling of hopelessness if the situation is not getting any better, especially if they are not as mobile as they once were or do not have the ability to access the help they need.''
He said feelings of hopelessness could easily lead to depression.
An individual who inflicted harm on others might have witnessed similar behaviour in childhood and come to see conflict and violence as a "normal'' model of how a family worked, Dr Tamatea said.
He said an abusive relationship between carer and victim could develop as the result of prolonged and increasingly "demanding and stressful'' situations, especially as the victim became more dependent and intensely reliant on the carer.
"The carer may begin to feel frustrated and look to shift the responsibility of their abuse to someone other than themselves, such as the demands of the victim.''
He said those who offended might also believe their actions were justified by their peers who might directly or by default reward their offending behaviour.
"Typically in people the fear of going to jail, or the experience of humiliation or shame when going to court are reasons enough for most people not to act in an antisocial way.''
The criminal psychologist said offenders' actions often involved thoughts, beliefs and attitudes that emphasised benefits or pay-offs for that behaviour.
"If violence has been seen to solve problems in the past then it increases the likelihood of future instances of violence to solve similar issues in the future.''
Expert Crown witness during Quinn's trial and Hawke's Bay District Health Board chief medical officer Dr John Gommans said it was difficult to determine when someone has become "vulnerable'' to neglect, as Maureen Quinn had.
"There is no hard and fast line to determine when a person is vulnerable and can no longer care for themselves. How much do you respect their wishes, while still looking after them?''
During Dr Gommans' testimony he said the condition of the 82-year-old was "something I've never seen''.
He also told the court the extensive wounds covering Maureen Quinn and the "sense of neglect'' had a "stunning'' impact on Hawke's Bay Hospital staff.
Medical staff would more commonly see dementia limiting the ability for people to care for themselves.
"What we want is for people to have enduring powers of attorney. To sign a document, while they are still capable, saying who will make decisions on your behalf if you no longer can, whether it be things like dementia, a stoke, or a something like a sudden head injury in a young person.''
The geriatrician said sometimes medical professionals discovered abuse of vulnerable people and while they were able to monitor the health of the victim, they often could not change social problems.
When a person was no longer able to care for themselves, Dr Gommans said a specialist psychologist or geriatrician would perform a series of tests with the person. Tests include questions such as who is the current Prime Minister, and being asked to explain how to make a meal.
He said such psychological tests were only performed if someone was deemed to have a medical health problem and gave consent.
If patients refused treatment, the medical fraternity and family members could use the Mental Health Act to seek care, usually in the cases of dementia and depression, he said.
"Sadly, help and care could only be given if medical professionals are aware of the case.''
Quinn was released on bail and will be sentenced on May 16.
