DENVER (AP) _ The father of slain child beauty queen JonBenet Ramsey says ``unskilled and unknowing'' Boulder investigators have wasted two years chasing the wrong suspects in his daughter's murder.

In a letter faxed to news organizations Monday, John Ramsey blasted the city's police force.

``We don't fault you for initially including us under your `umbrella of suspicion,' but we will forever hold you accountable for following a theory rather than the evidence,'' he wrote.

Boulder police declined to comment on the Ramsey letter.

The criticism follows a Sept. 20 resignation letter from investigator Lou Smit in which he argued that John and Patsy Ramsey had been unfairly targeted by police.

Police Chief Mark Beckner emphatically denied Smit's claim Sunday, saying, ``If he's aware of who the perpetrator is, I wish he'd let everybody know.''

JonBenet, 6, was found strangled and beaten in the basement of the Ramseys' Boulder home on Dec. 26, 1996. No one has been arrested, but police said the Ramseys remain ``under an umbrella of suspicion.''

Ramsey wrote that investigators ``had decided they had solved the case on the very first day by reaching the incredible conclusion that because the parents were in the house, they must have done it. ... The law in the hands of the unskilled and the unknowing is a terrifying thing.''

Earlier this month, a grand jury began hearing evidence in the case.

Legal analyst Scott Robinson called the Ramsey letter part of a continuing campaign by both sides to influence grand jurors, who have been ordered to avoid reading or watching news reports about the case.