Forgiveness and compassion are in the air.
First, NFL quarterback , Michael Vick, who served 18 months of a 23-month sentence in federal prison for running an illegal dog fighting ring, has made a comeback, vowing to work for the Humane Society of the United States and speaking out against animal cruelty.
The 29-year-old is out of the doghouse now, signed by the Philadelphia Eagles to play football once again.
Then, Susan Atkins, the notorious member of the Manson family, who held down pregnant Sharon Tate as the actress was stabbed 16 times in 1969, sought compassion.
Now 61, Atkins says she's a born-again Christian and will go before a California parole board in September to seek release because she is gravely ill with a brain tumor.
There's also Abdel Baset al-Megrahi, the only person ever convicted of the 1988 Pan Am 103 Lockerbie bombing, which killed 270 people, who was released from a Scottish jail this week to return to his native Libya to die of terminal cancer.
Upon the release Thursday, the Scottish justice secretary said he had been motivated by Scottish values to show mercy.
But forgiveness is a tricky business. The public is not always ready to embrace these civil decisions, and ethicists -- religious or otherwise -- say it takes more than the sweep of a judge's hand to wipe out a heinous crime.
"At least in two of the cases, what is common is they are both dying of cancer," said Thomas Reese, senior fellow at the Woodstock Theological Center at Georgetown University. "Society feels cancer is punishment enough and, frankly, the prisons don't want to take care of their medical needs."
In Catholicism, which veered from the "eye for an eye, tooth for a tooth" tradition in Judaism, forgiveness has been defined by a precise mechanism, Reese said.
You've got to be sorry for your sins. "God may forgive you," Reese said. "But we cannot welcome you back if you kill your wife and you're not sorry about it."
Confess your sins -- either before your community or your God.
Have a "firm purpose of amendment," Reese said. "If you are a mafia hit man, you can come in and confess the murder, but if you are planning on doing another one next week, that doesn't work."
Make penance. In a civil society, that means jail time, or community service or, as in Vick's case, making restitution or restoration by helping to prevent animal cruelty.
Vick an Easier Call Than Lockerbie Bomber
By that Catholic check list, Vick is off the hook. Some would say Atkins' crime is more heinous and her penance more severe, but "you've got to make a human judgment about whether her confession is sincere or not," Reese said.
Atkins, a former Charles Manson disciple, famously expressed no remorse in the Tate murder: "She [Tate] asked me to let her baby live," Atkins said at the time. "I told her I didn't have mercy for her."
"The parole board will have to decide if she is a danger to society, so that's a judgment call," Reese said.
But al-Megrahi -- whose release has drawn the most public criticism -- raises a question mark.
Al-Megrahi, 57, insisted he was innocent and has not shown compassion to the victims of the crash, many of whom were U.S. college students. Serving only eight years of his life sentence, he has been diagnosed with advanced prostate cancer.
"I'd be much more impressed if he said, as a Muslim, he now recognizes the act of violence was wrong and in violation of the Koran," Reese said. "But if he still believes what he does is justified and good, then that's problematic.
"For political and diplomatic reasons, Britain may have other reasons for releasing him, but he doesn't fulfill the checklist," he said.
Peter Singer, the Ira W. DeCamp professor of bioethics at Princeton University, sees no association between the Vick case and those responsible for mass murder.
As for al-Megrahi, "He should be shown no compassion for the people he killed," Singer said. "He showed no remorse and I think you shouldn't give someone less than 20 years for murder. For a lot of people, it sends the wrong message."
Animal Rights Founder Gentle on Vick
Singer, whose publication of the 1975 book "Animal Liberation" began the animal rights movement, is gentler on Vick.
"He's certainly shown remorse for what he has done and is seeking to make amends," Singer said. "He served his full term. Should you penalize someone on top of what the judge sentenced and never play football again?
"He is helping against dog fighting and working with kids to see that dog fighting isn't a cool thing to do. I see him as actually trying in some way to compensate, making good for the wrong thing he did."
Vick might even be a good role model, as he is allowed to "rehabilitate," he said.
Singer cited an old friend, Donald Barnes, who spent 16 years as a researcher doing "horrible experiments" on monkeys, but later became director of education for the National Anti-Vivisection Society, which seeks to eliminate the use of animals in product testing.
"He eventually saw it was wrong and was a spokesperson for the opposition," Singer said. "Those in the movement forgave him and accepted him as a supporter. People can generally forgive, but you want to do it with deeds."
Mass Murder Is Unforgivable
But many people queried by ABCNews.com, who asked not to be identified, have more venom in mind.
"It's been 30 years since my brother's murder, and I still don't feel that I could ever forgive the killer, and I certainly haven't forgotten what happened to our family because of it," said one.
"If we were ever lucky enough to meet the killer, I would still shake with anger and loss staring directly into his/her eyes. I do know that having that closure, I would feel better, but I don't think that I would ever forgive."
And the release this week in Lockerbie was particularly disturbing to some.
"I admire the Scottish judge's sense of compassion, but it should have been for the 270 innocents slaughtered," said another. "Would you have let Rudolf Hess go because he was getting old and had spent 40-odd years in Spandau prison [in Berlin]?"
"I am pretty outraged," said another. "He killed nearly 300 people and he's only served eight years in prison. It hardly seems just for him to go home to live out his last days with friends and family while he robbed so many people of the same."
"I do think that we should forgive people for their actions in many cases, but I don't know how I would feel if that were my husband, son or daughter on that plane," said another commenter.
But Rosamond Rhodes, professor of bioethics at Mount Sinai School of Medicine in New York City, confessed, "I am peculiar. I don't get it with forgiveness."
She said justifying the release of prisoners because they are "sick and dying" should have little to do with compassion. "It has to be consistent with the reasons for imprisoning them in the first place," she told ABCNews.com.
If Atkins was jailed to keep society safe, she might be justifiably released if "she has completely transformed herself and demonstrated she was not a threat to the community," Rhodes said.
"If one reason for punishment is to address the feeling of eye for an eye, that's not a good justification," she said. "More important is the justification that it protects from people doing it again."
Citing the Lockerbie bomber, she said, "If he is not in jail very long, you haven't achieved that goal. Also, if he is able to interact with his family and give encouragement to do things, he might still be dangerous -- or if he has symbolic value to his followers.
"For somebody [like al-Megrahi] who plans the murder of so many victims, it's hard for me to have that lump in the throat and let go," Rhodes said.
World Trade Center Families Let Go
But Grace Christ, a professor of social work at Columbia University in New York City, who has counseled the families of the firefighters who perished in the World Trade Center on 9/11, sees forgiveness differently.
"At first, they were very angry with the people they felt were responsible, and felt vindicated by the war and efforts to bring some of these people to justice," she told ABCNews.com.
"But, later, they really surprised us at how they really were not interested in getting revenge. They struggled with it, but it passed and they focused on maintaining their responsibility as parents and finding a way through it, looking forward."
The word "forgiveness" was never used in surveys of these families -- "that would have been provocative," Christ said. But as seen in the cultural acceptance of no-fault insurance and no-fault divorce, people are more willing to "seek reconciliation" rather than hold on to feelings of antagonism.
"I think we've learned a lot as society," she said. "We can lose our animosities. I think people are realizing it's much healthier."
Martha Alderman Boyer of Marietta, N.Y., lost her sister, Paula Bouckley and brother-in-law Glenn Bouckley, in the bombing of Pan Am Flight 103.
"I've gotten past being angry," she told ABCNews.com. "Certainly nobody will be forgotten, but I'm not angry. I can't say I'm angry."
"It's pointless, it just eats you up inside and makes you miserable," Boyer said. "What's the point? There is good that has come out of this, in many tragedies there is good that comes out of it."