A 33-year-old man pleaded guilty Wednesday to killing a Vancouver woman with a baseball bat in June 2011.Mitchell K. O’Brien pleaded guilty to second-degree murder in Clark County Superior Court in exchange for a reduction of the charge from first-degree murder. He also was exonerated of a charge of possession of marijuana in jail as part of the plea deal.The victim, Deneace L. McSpadden, also known as Lyla D. Hadley, 57, was a friend of O’Brien’s.Her daughter found her body on June 27, 2011, in the living room at her duplex at 1006 Morgan Road, off Middle Road north of state Highway 14. Near her body were a blood-stained aluminum baseball bat and significant blood spatter.An autopsy found that McSpadden had died of blunt-force head trauma. DNA evidence from the bat linked O’Brien, a convicted felon, to the slaying, according to a probable cause affidavit filed in court. Investigators were able to match the DNA profile to a DNA profile obtained from O’Brien’s skateboard, the affidavit says.O’Brien was serving a 41-month sentence at Stafford Creek Corrections Center in Aberdeen for a bank robbery that took place four days after the homicide when investigators arranged for him to be transported to Clark County to face a murder charge.O’Brien is scheduled to be sentenced Sept. 16. McSpadden’s family plans to participate in that hearing, said Chief Criminal Deputy Prosecutor Scott Jackson. Jackson and O’Brien’s attorney, Jeff Barrar of Vancouver, have agreed to jointly recommend a sentence of 200 months.