BBC correspondent Matt McGrath reports:

The importance of video evidence in courtrooms has grown in tandem with its supply in recent years. As well as the mountains of smartphone recordings, CCTV also routinely captures assaults, robberies and even murders. Some police officers even wear on-body cameras.

Courts all over the world are willing to accept these recordings in evidence and they are sometimes shown in slow motion, to help juries make up their minds about what really happened within the often chaotic environment of a crime scene.

A key point in many murder cases is the intention or otherwise of the accused. So the researchers carried out a number of experiments to determine the impact of slowing down the replay on observers.

In their first study, participants acting as jurors watched a video recording of an attempted robbery of a store, which ended with the shop assistant being shot dead.  They were shown either a regular speed or a slowed down version. Watching the slow-motion version quadrupled the odds that these mock jurors would begin their deliberations ready to convict.

The researchers believe that the slow motion version is giving observers the sense that those carrying out the violent acts on tape have more time to think and deliberate - and the observers therefore believe there is more intent in the violent actions.

“Bitterness is like drinking poison and waiting for the other person to die.” [Attributed variously]

“Holding a grudge is like letting someone live rent-free in your head.” [Author unknown]

“Bitterness is cancer - it eats upon the host.” [Maya Angelou (1928 – May 2014) was an internationally acclaimed American author, poet, most famous for her autobiography I KNOW WHY THE CAGED BIRD SINGS.]

“It is a simple but sometimes forgotten truth that the greatest enemy to present joy and high hopes is the cultivation of retrospective bitterness.” [Robert Menzies (1894 – 1978), was an Australian politician and the 12th Prime Minister of Australia.]

“When someone hurts you, cry a river, build a bridge, and get over it.” [Author unknown]

“AS I walked out the door toward the gate that would lead to my freedom, I knew if I didn’t leave my bitterness and hatred behind, I’d still be in prison.” [Nelson Mandela (1918 - 2013) was anti-apartheid revolutionary, politician and philanthropist who served 27 years in prison for his activism, and later became the President of South Africa from 1994 to 1999.]

“Never trust your tongue when your heart is bitter.” [Author unknown]

“Part of the problem with the word 'disabilities' is that it immediately suggests an inability to see or hear or walk or do other things that many of us take for granted. But what of people who ca't feel? Or talk about their feelings? Or manage their feelings in constructive ways? What of people who are't able to form close and strong relationships? And people who cannot find fulfillment in their lives, or those who have lost hope, who live in disappointment and bitterness and find in life no joy, no love? These, it seems to me, are the real disabilities.” [Fred Rogers (1928 – 2003) was an American educator, Presbyterian minister, songwriter, author, and television host, most famous for creating and hosting Mister Rogers' Neighborhood.]

“We live with the scars we choose.” [Author unknown]

“A bitter man needs to place his troubles on the front of his tongue so that they taste sweeter.” [Jay Wickre, author Dubious Musings of a Peculiar Man.]

“Bitterness: anger that forgot where it came from.” [Alain de Botton (1969 - ) is a Swiss writer, philosopher, and British television personality.]

“There’s no such thing as a bitter person who keeps the bitterness to himself.” [Erwin W. Lutzer (1941 - ) is an evangelical Christian pastor, teacher and author.]

“Every test in our life makes us bitter or better. Every problems comes to break us or make us. The choice is ours whether we become victim or victor.” [Author unknown]

“Bitter words normally evaporate with the moisture of breath, after a quarrel. In order to become permanent, they require transcribers, reporters, complicit black hearts.” [Barbara Kingsolver (1955 - ) is an American novelist, essayist and poet.]

“Up from behind a sand dune close beside her rose the form of her enemy Bitterness. He did not come any nearer, having learned a little more prudence, and was not going to make her call for the Shepherd if he could avoid it, but simply stood and looked at her and laughed and laughed again, the bitterest sound that Much-Afraid had heard in all her life.” [Hannah Hurnard, as quoted from Hinds' Feet on High Places.]

“Never be bitter, become better. A testimony is pain that has been reassigned” [Johnnie Dent Jr., is a modern American author, speaker, youth counselor and talk show host, dedicated to social reform in the African American community through the restorative power of the Gospel message.]

“Cries for justice are often the bitter laments of the vengeful.” [Wayne Gerard Trotman (1964 - ), is a British independent filmmaker, writer, photographer, composer and producer of electronic music.

“Unforgiveness is choosing to stay trapped in a jail cell of bitterness, serving time for someone else’s crime.” [Author unknown]

“Latent in every man is a venom of amazing bitterness, a black resentment; something that curses and loathes life, a feeling of being trapped, of having trusted and been fooled, of being the helpless prey of impotent rage, blind surrender, the victim of a savage, ruthless power that gives and takes away, enlists a man, and crowning injury inflicts upon him the humiliation of feeling sorry for himself.” [Paul Valéry (1871-1945) was a French poet, essayist, and philosopher.]

“Allowing bitterness into your life is like spraying yourself with a can of loving relationship repellant.” [Author unknown]

“The first to apologize is the bravest. The first to forgive is the strongest. And the first to forget is the happiest.” [Author unknown]

“Hatred is revenge against our own self for deeds committed by someone else." Author unknown

“If we could read the secret history of our enemies, we should find in each man's life sorrow and suffering enough to disarm all hostility.” Henry Wadsworth Longfellow (1807 – 1882) was an American poet and educator whose works include "Paul Revere's Ride," The Song of Hiawatha, and Evangeline.

“People that hold onto hate for so long do so because they want to avoid dealing with their pain. They falsely believe if they forgive they are letting their enemy believe they are a doormat. What they don’t understand is hatred can’t be isolated or turned off. It manifests in their health, choices and belief systems. Their values and religious beliefs make adjustments to justify their negative emotions. Not unlike malware infesting a hard drive, their spirit slowly becomes corrupted and they make choices that don’t make logical sense to others. Hatred left unaddressed will crash a person’s spirit. The only thing he or she can do is to reboot, by fixing him or herself, not others. This might require installing a firewall of boundaries or parental controls on their emotions. Regardless of the approach, we are all connected on this "network of life" and each of us is responsible for cleaning up our spiritual registry.” Shannon L. Alder is a modern American author and blogger.

“Probably the greatest harm done by vast wealth is the harm that we of moderate means do ourselves when we let the vices of envy and hatred enter deep into our own natures.” Theodore Roosevelt (1858 – 1919) was an American politician, author, naturalist, soldier, explorer, and historian who served as the 26th President of the United States.

“I don’t have time to hate people who hate me because I’m too busy loving people who love me.” Author unknown

“Fear is the most debilitating emotion in the world, and it can keep you from ever truly knowing yourself and others - its adverse effects can no longer be overlooked or underestimated. Fear breeds hatred, and hatred has the power to destroy everything in its path.” Kevyn Aucoin (1962 – 2002) was an American make-up artist, photographer and author.

“Holding a grudge like letting someone live rent free in your head." Author unknown

“Hatred like love seeds on the nearest trifles. Everything adds to it. Just as the we love can do no wrong, so the one we hate can do no right." Honore de Balzac (1799 – 1850) was a French novelist and playwright.

“Hatred, in the course of time, kills the unhappy wretch who delights in nursing it in his bosom.” Giacomo Casanova (1725 – 1798) was an Italian adventurer and author. His autobiography, Histoire de ma vie is regarded as one of the best sources of 18th century European social life.

“Hatred paralyzes life; love releases it. Hatred confuses life; love harmonizes it. Hatred darkens life; love illuminates it.” Martin Luther King (1929 – 1968) was an American Baptist minister, activist, humanitarian, and leader in the African-American Civil Rights Movement.

“Hatred, which could destroy so much, never failed to destroy the man who hated, and this was an immutable law.’ James A. Baldwin (1924 – 1987) was an American novelist, essayist, playwright, poet, and social critic.

“For the poison of hatred seated near the heart doubles the burden for the one who suffers the disease; he is burdened with his own sorrow, and groans on seeing another's happiness.” Aeschylus (c. 525/524 – c. 456/455 BC) was an ancient Greek tragedian playwright.

“Hatred is like acid—it will eat into your soul and kill you before you die.” J.M. White is a modern American poet, author and artist.

“Hatred is self-punishment.” Hosea Ballou (1771 – 1852) was an American Universalist clergyman.

“In hatred as in love, we grow like the thing we brood upon. What we loathe, we graft into our very soul.” Mary Renault (1905 – 1983) was an English writer best known for herhistorical novels set in Ancient Greece.

“Hatred and fear blind us. We no longer see each other. We only see the faces of monsters, and that gives us the courage to destroy each other.” Thich Nhat Hanh (1926 - ) is a Vietnamese ZenBuddhist monk, teacher, author, poet and peace activist.

“Some of our criticisms are unjust and unfair. They may come out of partial knowledge, or out of willfulness representation. What is one, then, to do? First of all, quickly breathe a prayer for your critics and for yourself. It is harder to hate people after you have prayed for them.” E. Stanley Jones (1884–1