BUFFALO, NY--  A man who killed a woman and her seven-year-old son will spend 50 years to life behind bars.

Shane Stevenson was sentenced in court Wednesday. He pleaded guilty to strangling Raina Voll, 30 and her son Leo Klinger in their Cheektowaga apartment last September. 

Another child, a toddler, was found abandoned in a church parking lot.  That child was unharmed and was placed in the custody of the child's biological father. 

Anna Voll, Raina's mother, said in court that her daughter was a great mom and that Leo loved life.

"The Cheektowaga police honed in on him and knew something was fishy going on there and that's why they were relentless in their investigation," said Erie County district attorney, John Flynn, "he only confessed that he did it he didn't elaborate at all on why he did this."

Anna Voll, Raina's mother read a statement to the judge -- she remembered her daughter as a great mom and friend, she called her daughter "the joy of our lives." She said her grandson, who was a second grader in the Depew School District, was a beautiful and smart boy. Anna Voll said she taught her children there are no monsters in life, but because of what Stevenson did, she says she won't be able to say that her grandchildren.