Sympathetic souls waiting to avenge the death of an innocent two-year-old child had a desperate night Tuesday as 12 jurors were not convinced that Casey Anthony murdered her daughter.

CNN's Nancy Grace summarized the feelings of those outraged by the verdict in the Casey Anthony trial when she said the 'devil is dancing tonight'.

Why was Casey Anthony let off?

The jury took 10 hours and 40 minutes to decide that the accused did not kill 2-year-old Caylee Anthony three years ago. It was a dramatic and controversial conclusion of the legal battle that had the nation riveted for over a month.

Surprisingly, the jury said Casey Anthony was not guilty of first degree murder, aggravated child abuse and aggravated manslaughter. She was found guilty only in four counts relating to the lies she told the investigators. The 25-year-old mother accused of killing her own child will be freed within days as she has spent two years in the prison already.

Even as the defense team cheered in jubilation inside the Orange County court house, agitated people outside erupted in anger. People expressed their fulsome anger in social media.

Despite presenting a mountain of circumstantial evidence against Casey, the prosecution failed to convince the jury that there indeed was damning physical evidence to prove that Casey was guilty of homicide.

The prosecution also failed to nail down the cause of Caylee's death.

According to legal experts, this was a verdict very few people who watched the trial had expected. Legal analyst Dan Abrams told ABC News that the jury focused particularly on very minute points of evidence, as it often happens in high profile cases. In this case there was no physical evidence, no trace of blood and no confession.

Apparently what nailed the prosecution attorney Jeff Ashton was the fact that he could never conclusively establish Casey's motive for killing daughter Caylee. The jury members did not have the 'burden of proof' while they had many reasonable doubts, it is argued.

Also court testimonies showed that there were many conflicting accounts of Caylee's disappearance. One such contradiction is the account of a woman called Crystal Holloway who said Caylee's death was an accident. The woman testified that she had an affair with Casey's father George. She said the death of Caylee was an accident that snowballed out of control.

Casey Anthony defense says the child died in a pool accident and the accused and her father covered it up. Casey's story is that she lied about Caylee's death because she was 'conditioned to lie'. She had also accused her father of sexually abusing her for years when she was a child, a charge George has denied in court.

Apparently the jury did not have enough clarity of the situation that they could hand a guilty verdict. They could not just dismiss those 'conflicting situations' as having no bearing on this case.

Casey Anthony was accused of murdering her daughter by applying chloroform first and sealing her mouth with duct tapes. Caylee's death took place in June 2008.

She wept in joy in court as she listened to the jury's announcement that she was 'not guilty' in three serious counts. Her lawyers praised the verdict and claimed justice was done. Attorney Jose Baez said this case proved why capital punishment doesn’t work. He said he is happy that he could save a life.

However, Baez admitted that there were no winners in the case. The mystery over how Caylee, the bubbly little girl with big brown eyes, died.

The devastated prosecution sat in stony silence after spending hundreds of thousands of dollars on the case and weaving the story of Casey's guilt with remarkable conviction. It was reported that Prosecutor Jeff Ashton was retiring in the aftermath.

Casey went back to protective custody hours after the verdict was announced. She may or may not get out on bail before Thursday's sentencing, depending on the defense stand.

The jurors refused to speak to the media after they pronounced the acquittal. Legal experts have said a retrial is near impossible in this case as it would be 'double jeopardy.' Casey will most probably walk free in days as she has already spent two years in jail.

Meanwhile people expressing their opinion on Twitter showed dismay at the verdict, and some even seethed with anger.

Scott Peterson was convicted based on circumstantial evidence. Seems like it was less than what Casey Anthony had in her hand, tweeted Terry McMillan.

Martha Stewart! lied JAIL 1 year!! Casey Anthony kills a kid... and goes home, said Brian-Bee.

Lohan goes to jail for a necklace and Casey Anthony is free. Makes perfect sense, tweeted chrissiemiller.

While some compared Casey Anthony trial outcome to other high profile cases, some others reserved harsh comments for the young mother who the world thought had killed her beautiful daughter.

Casey Anthony is the most hated woman on earth right now...Actually she's not a woman ...shes a monster. R.I.P Caylee, tweeted Ram Danielle.

It's not fair to compare Casey Anthony to OJ Simpson because OJ's kids are still alive, said Not Gary Busey.

For another Twitter user, the justice system in the country had failed abjectly. The casey anthony is yet another disappointment in our justice system. May god do his justice since america failed to do so, tweeted Alyssa Morales.

I am heart sick realizing the millions Casey Anthony will make on the blood of her precious lil' daughter,| said teri henson, referring to Casey's post-acquittal life of writing a memoir and making exclusive media appearances.

Everyone is saying if they ever see Casey Anthony they'll kill her, said Bayan Quran.

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