Jesse Frost, 39, of Riverbank, pleaded guilty to three counts of murder and one count of attempted murder for the February deaths of his mother, Donna Norton; sister, Judy Niemi; and brother-in-law Anthony Niemi. He also injured his nephew, Matthew James.
Norton was the sister of Oakdale Mayor Farrell Jackson and Niemi was his niece.
The plea agreement calls for Frost to receive three consecutive sentences of life without parole. As part of the agreement, Frost may not appeal the conviction, nor may he ever seek clemency or pardon. Frost also allocuted to the crimes, admitting that he stabbed the four people intending to kill them without any legal, ethical or moral excuse for doing so.
Frost will never be eligible for parole under the agreement.
In return for the pleas, the prosecution agreed not to seek the death penalty.
The case arose out of events that occurred in the city of Riverbank on Feb. 15. Frost stabbed all four people in a Riverbank residence where he was living, and then surrendered to the police.
Frost graduated from Riverbank High where he participated in several sports and excelled as a wrestler. He later went to Modesto Junior College where he won a California college championship in heavyweight wrestling.
Sentencing was set for Oct. 27 at 10 a.m. in Department 2.