Judge enters not guilty plea for dead tot's mother

By the Associated Press | November 17, 2011 | 12:25 PM EST

This photo provided Nov. 16, 2011, by the St. Louis County Police shows Shelby Dasher. Dasher was charged Wednesday, Nov. 16, with second-degree murder in the death of her son, Tyler, whose body was found discarded near a cemetery about a mile from home on Tuesday, hours after she reported him missing. (AP Photo/St. Louis County Police)

CLAYTON, Mo. (AP) — A St. Louis County judge has entered a not guilty plea on behalf of Shelby Dasher, the young mother accused of killing her 13-month-old son because he wouldn't stop crying.

The 20-year-old Dasher made a brief court appearance Thursday during which the judge also assigned the public defender's office to represent her.

Dasher was charged with second-degree murder on Wednesday, a day after she reported that her son, Tyler, was missing from his crib. The boy's body was found a few hours later in a field near the home in Affton where he lived with his mother and grandmother.

Prosecutors say Dasher confessed to striking the boy out of frustration.