A man arrested Dec. 21 and said by Fairfax County police at the time to be suspected of being the Reston "pathway rapist" was freed yesterday after a 70-year-old rape victim said in court she could not identify him as her assailant.

County prosecutors dropped the single rape charge against Melvin J. Timbers, 19, after the victim testified at a preliminary hearing in Fairfax General District Court. Later Timbers was released from the county jail, where he had been held under $75,000 bond.

Police Chief Carroll D. Buracker, who had said at the time of the arrest that Timbers was regarded as a suspect in two other rapes on pathways in the south Reston area as well as the one with which he was charged, said yesterday: "We're going to have to reassess the entire case."

Buracker said Timbers was arrested after the 70-year-old woman picked his picture out of a number that were shown her. "She said it was positively him," Buracker said yesterday.

The woman had been assaulted Sept. 1 while walking on one of Reston's wooded pathways.

Yesterday, when the woman was asked if she could identify her assailant in the courtroom, she took several long looks at the audience before she looked at Timbers and his attorney seated at the defense table. After 10 or 15 seconds, she said she did not see the man who raped her.