The 15-month-old investigation into JonBenet Ramsey's killing may finally be heading for a grand jury, the head prosecutor hinted.

"It has been an option for a long time, and it has become a matter of more serious consideration at this point in time," District Attorney Alex Hunter said Monday.He declined to elaborate except to say, "We are evaluating if there is a basis (to convene a grand jury) and if it would advance the investigation."

Lawyers for the family of the slain 6-year-old beauty queen declined to comment.

Grand jury proceedings, which are secret, are sometimes used to force uncooperative witnesses to testify.

A grand jury may issue an indictment to arrest someone for probable cause, a lower standard than the threshold of beyond a reasonable doubt that must be met to find someone guilty at trial.

Hunter's office rarely uses grand juries, but some detectives have been pushing for one in this case.

JonBenet was found strangled and beaten in the basement of her home on Dec. 26, 1996, hours after her mother reported finding a ransom note.

Her millionaire father and mother, at odds with police almost since the investigation began, haven't been ruled out as suspects.