A 21-year-old North Potomac man was sentenced to life in prison Thursday for murdering his father while on holiday leave from the U.S. Marines in 2007.

David Winters was convicted and found criminally responsible in January 2009 of first-degree murder of his father, architect Andrew Winters, who was found dead with 65 stab wounds and slashes near a pond in Muddy Branch Park.

Winters, who had previously been diagnosed with paranoid schizophrenia, pleaded not criminally responsible.

"It's the judgment of the court that Mr. Winters poses a grave and serious danger to society," Montgomery County Circuit Court Judge William J. Rowan III said at the sentencing. "He's wrongfully taken the life of another, and someone, as I've indicated, who was extremely close to him, with clever, thorough and brutal planning and actions."

Rowan said he would recommend that Winters serve his sentence at Patuxent Institution, a correctional mental health center in Jessup.

The defense had sought a sentence of less than 35 years.

Neither Winters nor his attorneys made statements at the sentencing.

Just days before Thursday's sentencing, Winters' attorneys filed a motion to re-evaluate Winters' competency at the time of the murder. The document, dated Aug. 27, said the original evaluation may have been flawed and included two handwritten letters from Winters.

"I am truely (sic) sorry for what I did. I could not control myself," Winters wrote in a letter dated Dec. 18, 2009. "And I realize I need to be on medication to treat my illness. Please consider an appeal, however possible."

Winters' attorney, Myra Kovach, declined to comment Friday.

Assistant State's Attorney Carol Crawford did not immediately return a call for comment Friday. Prosecutors said that on Dec. 25, 2007, Winters and his father went for an evening walk in the woods near the family's home, where Winters stabbed him with a hunting knife. The murder weapon was found at the bottom of a nearby pond, according to the Montgomery County State's Attorney's Office.

On the day before the murder, Winters purchased the knife and asked an uncle about his father's ability to defend himself, prosecutors said.

Winters was expected to be sentenced in March, but the date was pushed back until Winters was deemed competent.

sgantz@gazette.net