Atlanta (CNN) -- A Georgia judge Thursday sentenced Hemy Neuman to life in prison without the possibility of parole after jurors convicted him of fatally shooting a father outside a suburban Atlanta day care center.
DeKalb County Judge Gregory Adams delivered the sentence less than two hours after a jury of nine women and three men found Neuman guilty of malice murder "beyond a reasonable doubt, but mentally ill."
"This situation was brought about by your hands," Adams said, adding that the act "appeared to be a planned execution."
In November 2010, Russell "Rusty" Sneiderman was shot multiple times in the parking lot of Dunwoody Prep after dropping off his then-2-year-old son in what police described as a "cold and calculated murder."
The jury had three options, after beginning deliberations Tuesday: to find Neuman guilty of murder, to find him guilty but mentally ill or to find him not guilty by reason of insanity, as he'd pleaded.
They chose the second course. That meant Adams could either have sentenced Neuman to life in prison with the possibility of parole in at least 30 years, or life in prison without the possibility of parole.
Neuman will be evaluated for mental illness in prison, and if diagnosed as mentally ill will be treated while incarcerated.
After the verdict was delivered, Steve Sneiderman described his 36-year-old brother as a "good provider," "devoted son," "wonderful brother" and a "great father" to his two children.
"He had limitless potential, which now can never be realized because of this man," Sneiderman told the court Thursday, referring to Neuman.
Neuman himself spoke a short time thereafter, saying "everybody lost" in this case -- making specific reference to Sneiderman's son and daughter and his own three children. He called the man that he killed "a good man."
"I am so, so, so sorry. I can't say it enough," Neuman said.
During closing arguments and again Thursday after the sentence was handed down, defense attorney Doug Peters claimed that the victim's widow had "manipulated our client, who was mentally sick."
"I believe she preyed upon him and used him to commit the crime that she is responsible for," Peter said Thursday, noting that he did not believe that Andrea Sneiderman knew specifics of the shooting plan even as he suggested she inspired it.
She has not been charged.
Following the sentencing, DeKalb County District Attorney Robert James did not elaborate on whether Andrea Sneiderman might be charged later. He said only that "it is something that we have under review right now."
"Justice has been served here," James told reporters, saying the focus Thursday should be on Rusty Sneiderman and not his widow. "I want to thank God that finally, after a year and a half or more, this family -- a good family -- is able to begin the process of healing."
At the time of the shooting, Neuman was Andrea Sneiderman's supervisor at work and both the defense and prosecution accused her of having an affair with the defendant. She denied the accusation in her testimony during the trial.
"There was no affair. Who kills someone else's husband?" Andrea Sneiderman said, claiming that Neuman said he'd cared about her, her husband and her family before the shooting.
The jury also found Neuman guilty of using a firearm in the commission of a felony. Adams sentenced Neuman to five years in prison for that charge, to be served concurrently with his life sentence.
Witnesses testimony and evidence presented during the trial showed Neuman tried to disguise himself, staked out the victim, conceal his plan and later conceal evidence tied to the shooting.
On the day of the murder, witnesses told police they saw a man -- later proven to be Neuman -- come up from behind Sneiderman and open fire in Dunwoody, a community about 15 miles north of Atlanta. The shooter then fled the scene in a silver minivan without a valid license plate.
Sneiderman, a native of Cleveland, Ohio, received an MBA from Harvard and was an active volunteer with the Georgia chapter of the Cystic Fibrosis Foundation.
Neuman, then 48, was arrested nearly two months after the shooting.
During his trial, which began last month, the prosecution had argued that Neuman was not insane.
James, the district attorney, urged jurors to "use your common sense ... and you apply it to determine whether or not somebody is malingering or telling the truth."
"He's insane, he sees angels, he sees demons, he's crazy. 'Something's wrong with me,'" James said, repeating assertions made by Neuman and his defense team. "If you cannot trust the ingredients on this insanity sandwich, then I'm going to ask you -- don't eat it."
Doug Peters said that he and other defense team members plan to talk soon with Neuman, to discuss what their next step will be. But he suggested that an appeal should be forthcoming.
"We still do believe that a jury should return a verdict of not guilty by reason of insanity," Peters said. "We didn't get that this time, but we're not about giving up."
An attorney for Andrea Sneiderman released a statement late Thursday saying her client "is grateful for and relieved by the jury's guilty verdict and sentence."
"Nothing can bring back her husband, but it is reassuring to her that, after all of the noise and distractions surrounding this case, some measure of justice has been done for Rusty," said the lawyer, Jennifer Little.
InSession's Nancy Leung contributed to this report.