BOULDER, Colo. (AP) _ After analyzing three handwriting samples from JonBenet Ramsey's mother, investigators have asked for another.

Patsy Ramsey agreed to hand over a fourth sample to authorities investigating the death of the 6-year-old beauty queen, family spokeswoman Rachelle Zimmer said Thursday. Authorities wouldn't say why they asked for an additional sample.

``She has given us handwriting samples before. We have asked for additional examples,'' said Boulder District Attorney Alex Hunter. ``All along the course of the investigation there have been many requests for handwriting from a number of different people.''

Zimmer said that the request for Mrs. Ramsey's handwriting ``was limited in scope'' and she ``immediately agreed to provide'' it.

Police have obtained several handwriting samples from Ramsey family members and others in an attempt to determine who wrote a ransom note found in the family's home Dec. 26.

The former Little Miss Colorado was found beaten and strangled in the basement about eight hours after the note was discovered.

Mrs. Ramsey provided a third sample of her handwriting last month after police decided the first two submissions were suspect because she was taking medication, police spokeswoman Leslie Aaholm said.

Handwriting experts have concluded JonBenet's father, John Ramsey, did not write the note demanding $118,000 for his daughter, according to published reports.