do you mean this type of death penalty?
http://en.wikipedia.org/wiki/Apostasy_in_Islam
The definition and appropriate punishment for apostasy in Islam is controversial, and it varies among Islamic scholars.
In Islamโs history, the vast majority of scholars have held that apostasy in Islam is a crime punishable with the death penalty, typically after a waiting period to allow the apostate time to repent and return to Islam
Apostasy in Islam includes in its scope not only former Muslims who have renounced Islam to join another religion or become non-religious, but Muslims who have questioned or denied any "fundamental tenet or creed" of Islam such as Sharia law, or who have mocked Allah, worshipped one or more idols, or knowingly believed in an interpretation of Sharia that is contrary to the consensus of ummah (Islamic community).
The term has also been used for people of religions that trace their origins to Islam, such as Bahรก'รญs in Iran, and Ahmadiyya Muslims in Pakistan and Indonesia.
According to critics, punishment for apostasy in Islam is a violation of universal human rights, and an issue of freedom of faith and conscience
or this type of death penalty?
http://www.wsj.com/articles/egyptian-court-sentences-183-people-to-death-1422877602
The ruling comes amid continued international criticism of Egyptโs use of mass trials to prosecute hundreds of people on similar charges.
It also occurs a day after authorities deported Peter Greste, an Australian journalist for the Al Jazeera news network who served 400 days of a 7-year sentence for reports the government deemed harmful to the countryโs national security.
Mondayโs court ruling stems from the convictions in December of 188 people for murder during antigovernment protests in August in the town of Kerdasa, near Cairo.
The protests erupted after police cracked down on two protest camps in the capital, leaving some 1,000 members of the Brotherhood and their supporters dead.
In its decision Monday, the court also acquitted two people and sentenced a third, a minor, to 10 years in prison. The convictions of two others were vacated because they had died.
death penalties for defenceless baby killers..... I say........ off with their head..... how about you ??? 
http://en.wikipedia.org/wiki/Death_of_Azaria_Chamberlain
Lindy Chamberlain was tried for murder, convicted on 29 October 1982 and sentenced to life imprisonment. Azaria's father, Michael Chamberlain, was convicted as an accessory after the fact and given a suspended sentence.
The media focus for the trial was unusually intense and aroused accusations of sensationalism, while the trial itself was criticised for being unprofessional and biased.
http://listverse.com/2013/03/27/10-people-who-were-wrongfully-accused-of-heinous-crimes/
In June 1982, forty-nine gold bars were stolen from the Perth Mint in Western Australia, at an estimated worth of more than two million dollars in todayโs money. Police quickly suspected three brothersโRay, Peter, and Brian Mickelbergโof the crime, and they were quickly found guilty and sentenced to a long period in prison.
As you can probably guess, they didnโt do it.
The Perth Mint Swindle, at it is commonly known, remains unsolved to this dayโbut the Mickelbergs werenโt cleared of all charges until 2004.
The brothers have repeatedly stated that police framed them from the start. Brian was released after less than two years but died in a plane crash soon afterwards, while Ray and Peter served eight and six years in jail, respectively.
In 2002, a police officer who had working on the case admitted to having fabricated evidence, and also beating Brian while he was in custody.
