Wrenching case of child manslaughter ends in 20 year prison sentence

MADISON, S.D. – In a courtroom overflowing with emotion, the death of a child at the hands of Amanda Walder, a mother herself, brought grief, condemnation and the wrenching question, “why?,” from the grieving mother of Liam Koistinen, the 16-month-old son of Jeff and Genevie Koistinen.

In the case of the State of South Dakota versus Amanda Walder,  the 32-year-old woman, who was charged with manslaughter in the first degree from a plea agreement entered and accepted by the court in March 2023, has been sentenced to 20 years in the Women’s State Penitentiary with 29 days credit for time served and restitution of over $145,000 plus court costs and County Attorney fees. No parole options were mentioned. 

The prosecution had  requested 50 years in the Women’s State Penitentiary. It was said that they were “not here for vengeance,” but justice needed to be served. 

Third Judicial Circuit Court Judge Carmen Means, who had just marked 10 years as a Judge in April 2023, presided over the case.  Judge Means called the case the single, most emotional case she has presided over. She said she understands emotions were and are high but asked the crowd to respect the court. 

Walder was initially charged with murder – second-degree, two counts of manslaughter, first-degree, aggravated battery of an infant, and abuse/cruelty of a minor under seven years of age. The prosecution dismissed the four other charges. Walder entered the plea agreement on March 16, 2023, and  Judge Means allowed Walder to remain out on $50,000 bail.  

Attorneys for the State of South Dakota were Kelly Marnette and Robert Mayer. The attorney’s for Amanda Walder included criminal defense attorney Clint Sargent and Donald McCarty. 

Judge Means allowed anyone from the family to speak. Jeff Koistinen spoke first. In an emotional statement, he said Liam was, “stolen from us in a senseless act of violence” with “cruel and vicious treatment.” He continued by stating Walder waited until Liam was unresponsive before contacting him. Repeatedly he said, “All because she couldn’t pick up the phone and call us.”

Genevie Koistinen spoke in tears, “Why!” “I hate her so much for what she’s done to my son!” She had a video she requested the Judge see before the decision, but the Judge declined and said if she wanted her to watch it after the sentencing to give her peace, she would.  

Amanda Walder spoke from a prepared written statement. Through tears she said she was, “sorry for the heartbreak and loss” she caused. She said she wished Liam was still alive and the events of that day had never happened.  

Defense attorney McCarty addressed some of the comments made by the family, disagreed with the sentencing suggestion, and countered with 10 years. He also mentioned the 47 letters sent to the prosecution about Amanda Walder and how she’s positively lived her life. The prosecution also noted in his 35-year career, that he has never seen that many letters of character. Most were positive about Amanda Walder. 

Before Judge Means’ sentencing, she commented that she disagreed with a statement made about a two-tier system of justice based on politics. She did say, however, she understands that people with “the means” are different from those who don’t have “the means” and there can be differing results. 

Judge Means said, “No sentence in the world can bring Liam back or bring closure to the parents. But there must also be a message sent of deterrence to the public.”