Coldhearted Robin Kalinowski murdered her hus­band after he learned she was having an affair – then tried to hire a hit man to kill her lover so he couldn’t testify against her!

“She is not someone you would want to have a relation­ship with,” prosecutor Thomas Finnerty told The ENQUIRER.

Robin, 46, had been married to her husband, Kevin, a 41-year-old carpenter, for 15 years. He was an avid hunter and coached their sons’ Little League baseball teams.

At the the time of the murder, authorities say Robin was hav­ing an affair with her co-worker, John Carey. The two worked at a social services agency in Buf­falo, N.Y., where Robin lived.

“They had sex at work and at her home,” said Finnerty, an Erie County assistant District Attorney.

When Kevin discovered the affair, he confronted Robin and told her he was going to seek custody of their boys, Kevin Jr., 11, and Erik, 9.

“A divorce would have been one thing,” said Finnerty. “But the prospect of losing her kids was too much for her.”

On the night of Nov. 10, 2005, authorities say Robin shot Kevin in the back of the head at point-blank range as he slept – with a rifle he had given their older son as a gift.

“Kevin never had a chance,” continued Finnerty. “She killed him because of her fear of what she might lose. When she pressed the rifle against the back of his head, she executed him. It was an intentional, deliberate execution. She’s a sociopath.”

Robin claimed it was an acci­dent. She said Kevin had gone to bed with the rifle by his side, a bullet in the chamber and the safety off, and it had gone off when she picked it up as she got into bed in the dark at 1:00 a.m.

“Her whole story was ridicu­lous,” said Finnerty.

“People having affairs don’t accidentally shoot their hus­bands in the back of the head.

“Kevin was a very experienced hunter and multiple witnesses testified about how safe and con­scientious he was with guns.”

But Robin was even more de­vious than anyone could have imagined. While in jail await­ing trial for Kevin’s murder, she tried to convince her cell mate to help her find a hit man to kill her lover so he could not testify against her.

“We sent in an undercover officer, posing as a hit man, and we recorded her offering him $3,000 to kill Mr. Carey,” said Finnerty.

Robin was tried three times for the murder. The first tri­al ended in a hung jury; in the second, she was convicted but it was overturned. But on March 1 of this year, she was found guilty of second-degree murder and was later sentenced to 25 years to life. She had already pleaded guilty to conspiracy to murder Carey in 2010.

Meanwhile, their kids are living with her relatives.

“It’s been a long time and she finally got what she deserved,” said Kevin’s sister, Laurie Bot­win. “There has never been any doubt in my mind that she did this.”