Aspen—-The case is closed in the murder of lifelong Aspen resident Nancy Pfister.  66 year old William Styler pled guilty today to second degree murder and was immediately sentenced to 20 years in prison.  The former Denver anesthesiologist who is now in failing health and in a wheelchair, admitted to prosecutors he hit Pfister in the head with a hammer while she slept on the night of February 24th.  Pfister was 57.  Her bludgeoned body was found two days later in a bedroom closet of her home on West Buttermilk Road.  Styler’s plea and sentence comes on the heels of murder charges being dropped against Styler’s wife Nancy and Pfister’s assistant and property manager Katherine Carpenter.  The Stylers rented Pfister’s home while she was on vacation in Australia.  Pfister had to cut her travels short because the Stylers hadn’t paid the rent and she was killed not long after her return.  Pfister’s parents co-founded the Buttermilk Ski Area.