Why are liberals generally opposed to the death penalty?

Answer by Kris Rosvold:

In THEORY, I have no problem at all with capital punishment, so long as we have a way to insure that no innocent person is EVER killed for something they did not do. We Don't.

That, my friend, is the entirety of the problem… off the top of my head, I know of at least TWO dozen who were on death row for crimes THEY DID NOT COMMIT!

How could you live with yourself knowing you had sent an innocent to death??!

As Mr. Jefferson (I think) once said "I would rather that ten guilty men go free, than that an innocent man spend one day in jail!"

4/15/14 Edit after a discussion with a fellow Quoran:

*Begin rant*

The  key difference is that, if you are dead and then found innocent (which  has happens repeatedly in nations which use the death penalty) there is  no way to rescind that sentence or make any attempt at correcting it.   Also, at least in the US, a factually innocent person being incarcerated  is not at all uncommon!  DAs, cops, even the FBI Crime Labs,  OFTEN trump up (falsify) evidence on the theory that "If they got caught  doing this other, unrelated crime, they must be guilty of the charged  crime on some level."

Worse yet, EVERY SINGLE DA, without  exception, has actively, aggressively, and vigorously fought, EVERY  SINGLE exoneration even when presented with proof positive that the  person convicted was the WRONG PERSON.  This??!   From people who are  supposedly SWORN to insure Justice and who are required, by law, in most  States, to present exonerating evidence to the Court?

Folks,  The simple fact is: Our "Justice" System has absolutely nothing to do  with justice and everything to do with how much money you can pay an  attorney for your defense.
*End Rant*

Backup Data (highlighted in bold as needed):

See the Following from The Innocence Project – Home

"There have been 316 post-conviction DNA exonerations in the United States.

• The first DNA exoneration took place in 1989. Exonerations have been won in 36 states; since 2000, there have been 249 exonerations.
• 18 of the 314 people exonerated through DNA served time on death row. Another 16 were charged with capital crimes but not sentenced to death.
• The average length of time served by exonerees is 13.5 years. The total number of years served is approximately 4,232.
• The average age of exonerees at the time of their wrongful convictions was 27.
Races of the 316 exonerees:
198 African Americans
94 Caucasians
22 Latinos
2 Asian American

• The true suspects and/or perpetrators have been identified in 153 of the DNA exoneration cases.
•  Since 1989, there have been tens of thousands of cases where prime   suspects were identified and pursued—until DNA testing (prior to   conviction) proved that they were wrongly accused.
• In  more than 25 percent of cases in a National Institute of Justice   study, suspects were excluded once DNA testing was conducted during the   criminal investigation (the study, conducted in 1995, included 10,060   cases where testing was performed by FBI labs).
• 65  percent of the people exonerated through DNA testing have been   financially compensated. 29 states, the federal government, and the   District of Columbia have passed laws to compensate people who were   wrongfully incarcerated. Awards under these statutes vary from state to   state.
• An Innocence Project review of our closed cases from  2004 – 2010  revealed that 22 percent of cases were closed because of  lost or  destroyed evidence.
• The Innocence Project was  involved in 172 of the 316 DNA  exonerations.  Others were helped by  Innocence Network organizations,  private attorneys and by pro se  defendants in a few instances.
• 30 of the DNA exonerees pled guilty to crimes they did not commit.
Leading Causes of Wrongful Convictions

These DNA exoneration cases have  provided  irrefutable proof that wrongful convictions are not isolated  or rare  events, but arise from systemic defects that can be precisely  identified  and addressed. For more than 15 years, the  Innocence Project has worked  to pinpoint these trends. Many wrongful  convictions overturned with DNA  testing involve multiple causes. 

Eyewitness Misidentification Testimony was a factor in 73 percent percent of post-conviction DNA exoneration  cases in the U.S., making it the leading cause of  these wrongful  convictions. At least 40 percent of these eyewitness  identifications  involved a cross racial identification (race data is  currently only  available on the victim, not for non-victim  eyewitnesses). Studies have  shown that people are less able to  recognize faces of a different race  than their own.  These suggested  reforms are embraced by leading  criminal justice organizations and have  been adopted in the states of  New Jersey and North Carolina, large  cities like Minneapolis and  Seattle, and many smaller jurisdictions. Read more.

Unvalidated or Improper Forensic Science played  a role in approximately 50 percent of wrongful convictions later  overturned by DNA testing. While DNA testing was developed  through  extensive scientific research at top academic centers, many other  forensic techniques – such as hair microscopy, bite mark  comparisons,  firearm tool mark analysis and shoe print comparisons –  have never been  subjected to rigorous scientific evaluation. Meanwhile,  forensics  techniques that have been properly validated –  such as serology,  commonly known as blood typing – are sometimes  improperly conducted or  inaccurately conveyed in trial testimony. In  other wrongful conviction  cases, forensic scientists have engaged in  misconduct. Read more.
False confessions and incriminating statements lead  to wrongful convictions in approximately 25 percent of cases. Looking  only at the homicide cases, false confessions are the leading   contributor to wrongful convictions, contributing to 64 (62%) of the  104  homicide wrongful convictions that were overturned by DNA  evidence,  where as misidentifications contributed to only 32 (31%) of  the homicide  wrongful convictions.  Twenty-nine of the DNA exonerees pled guilty to crimes they did not commit. The Innocence Project encourages police  departments to electronically  record all custodial interrogations in  their entirety in order to  prevent coercion and to provide an accurate  record of the proceedings.

Informants contributed  to wrongful convictions in 18 percent of cases. Whenever  informant  testimony is used, the Innocence Project recommends that the  judge  instruct the jury that most informant testimony is unreliable as  it may  be offered in return for deals, special treatment, or the  dropping of  charges. Prosecutors should also reveal any incentive the  informant  might receive, and all communication between prosecutors and  informants  should be recorded. Read more."

Why are liberals generally opposed to the death penalty?