An Arroyo Grande man was sentenced Tuesday to 56 years to life in state prison for the first-degree murder of a San Luis Obispo woman.
A jury convicted Robert Koehler, 40, on July 14 of slashing 26-year-old Kristen Marti's throat and weighing her body down with rocks in Prefumo Canyon Creek in January 2018.
Before Koehler's sentencing hearing began in San Luis Obispo Superior Court, defense attorney Trace Milan argued for a new trial for about an hour and a half - claiming his client did not receive a fair trial for various reasons.
However, Superior Court Judge Jesse Marino ultimately disagreed and denied the motion.
Milan told The Tribune he plans to file a notice of appeal for the conviction Wednesday.
A first-degree murder conviction carries a sentence of 25 years to life in state prison, which was doubled for Koehler because he had a strike for a carjacking in 2005. An extra year was added for the use of a deadly weapon, a knife, and five years for serving a prior prison term, totaling in a sentence of 56 years to life.
That was the maximum sentence Koehler could receive.
