Roberto Recendes, accused of attacking a 94-year-old Palo Alto woman in 2002, pleaded not guilty to sexual-assault and elder-abuse charges on Friday in the North County Courthouse in Palo Alto.

Recendes allegedly assaulted the woman in her Palo Alto Commons assisted-living apartment in south Palo Alto in 2002.

He is charged with penetration with a foreign object, infliction of great bodily injury and elder abuse committed during a burglary, according to Santa Clara County Deputy District Attorney Brian Welch. Recendes could serve life in prison if convicted.

The woman died in 2006.

Recendes' plea is long-awaited. Palo Alto police initially arrested Jorge Hernandez of Mountain View, based on a lengthy police interview during which detectives believed he admitted the assault -- despite emotional denials to his older brother during an interlude in the interrogation.

Hernandez spent weeks in jail until he was completely cleared of the assault by DNA evidence. Hernandez did say he was highly intoxicated and recalled features of the woman's ground-floor apartment. He told police he was with two other men but couldn't remember their names. His brother's class ring was also found at the scene.

The DNA evidence eventually linked Recendes to the crime, when he was released from state prison in 2007 and was required to provide a sample of his DNA. He moved back to Mexico but was extradited to Santa Clara County in August 2008.

Welch said the year-long wait for a plea was due to repeated continuances requested by Recendes' public defender, Carl Beatty, who had his own experts review the DNA reports.

Due to the nature of the crimes, there was never any discussion of a possible plea deal, Welch said.

The case could be moved from Palo Alto to San Jose due to the possibility that the trial could last more than a week, he said.

Recendes will return to court in Palo Alto on Nov. 6 for a preliminary hearing.