By Ellen Wulfhorst

NEW YORK (Reuters) - An Occupy Wall Street protester convicted of assaulting a police officer during a demonstration two years ago was sentenced on Monday to a 90-day jail term.

A New York jury on May 5 found Cecily McMillan guilty of elbowing a police officer, Grantley Bovell, in the eye as he was attempting to arrest her.

McMillan, 25, was arrested along with scores of others on March 17, 2012 at a demonstration marking the protest movement's six-month anniversary in New York City.

While thousands of people were arrested during Occupy protests in 2011 and 2012, most of those cases were dismissed, some were resolved out of court and just 67 have gone to trial.

An "unprecedented amount of time and care" was given to the more than 2,600 cases that arose during the Occupy movement and were handled by the Manhattan District Attorney's office, said Erin Duggan Kramer, deputy chief of staff, in a statement.

"This defendant chose to take her case to trial, and was convicted by a jury of her peers for a violent felony," she said.

McMillan's lawyer argued that his client was reacting to someone groping one of her breasts, according to media accounts of the trial. Prosecutors said that claim was a fabrication.

In a statement prepared for the sentencing hearing, prosecutor Shanda Strain said McMillan tried to use her trial "as a grandstand for her political opinions."

"She seeks to be perceived as a martyr and to gain fame from her involvement in this case," she said in the statement.

The 90-day sentence, followed by five years probation, was handed down by New York State Court Justice Ronald Zweibel and requested by prosecutors. McMillan had faced a potential sentence of as much as seven years in prison.

At her sentencing, McMillan proclaimed her innocence, according to local media.

"Whether personal or political, violence is not permitted. This being a law that I live by, I can say with certainty that I am innocent of the crime I have been convicted of," McMillan was quoted as saying by the Huffington Post.

McMillan is one of 56 people to be convicted at trial, while another 11 people have been acquitted.

The populist movement protesting economic inequality got its start in a downtown Manhattan park. Occupy inspired dozens of spin-offs around the world with its "We are the 99 percent" slogan but drew criticism for its unclear goals.

(Additional reporting by Bernard Vaughan; Editing by Tom Brown)