The father of JonBenet Ramsey is making a public plea for help in finding his daughter's killer 13 years after she was found strangled in the basement of her family's Colorado home.

John Ramsey said in a statement Wednesday that he is asking people to share any suspicions they had or recollections of people acting strangely around the time the 6-year-old girl died.

JonBenet. who was born in Atlanta and is buried in Marietta, Ga., was found bludgeoned and strangled Dec. 26, 1996.

A former prosecutor said at the time that Ramsey and his wife, Patsy, were "under an umbrella" of suspicion, but authorities cleared them in 2007. Authorities said new DNA tests pointed to an unknown outsider.

Police continue to investigate the case.

Patsy Ramsey died from cancer in 2006.