The family of a Tulsa man who was murdered is shocked and outraged the killer is now a free man after serving 11 years of his 32-year sentence.

The Tulsa County District Attorney is also frustrated by how the state calculates prison sentences.

The family of Neal Sweeney and Tulsa County D.A. Steve Kunzweiler both say a day in prison should be counted as one day.

But in some cases, prisoners are getting 100 days credit for every single day they serve.

Mohammed Aziz is now a free man after being convicted of getting a man to kill Sweeney in 2008.

Sweeney was a husband, father, and Tulsa businessman.

Aziz got credits for good behavior and taking classes like Anger Management and Life Skills.

Kunzweiler says it’s frustrating not to know how much of a sentence criminals will actually serve.

"After they leave here and they go to the Department of Corrections, there's a calendar that exists that I've never been able to find,” said Kunzweiler. “It's virtually impossible to understand what credits anybody's going to earn."

The family of Neal Sweeney told News On 6 “It’s wild to me that he can get credit for days served without actually having served that many days in real life. Serving 30 days monthly yet having it counted as 100+ was never part of the plan we agreed to. He was proud of murdering my father and there’s no way I will ever believe that some course he took made him gain empathy or human decency.”

The Sweeney family says they were only given four days' notice Aziz would be released because of a prisoner notification program they signed up for.

Kunzweiler says it’s hard to tell victims' families like the Sweeneys, that the person who killed their loved one will be free.

He advises families to always sign up to track prisoners.

"Know who the case manager is, be speaking with the case manager, get continued updates,” said Kunzweiler. “But that's not easy, if you've lost a loved one, who wants to be calling somebody to be checking on someone who killed your family member. I wouldn't want to do that."

The way the Department of Corrections calculates time is set by state lawmakers.

Prosecutors and victims’ families hope people will pressure lawmakers to make changes.