New York (CNN) -- A film student suspected of stabbing a New York cab driver after learning the driver was Muslim was described Thursday as someone who worked to build bridges across religious and ethnic boundaries.
Those who know Michael Enright, 21, a film student at the School of Visual Arts in Manhattan, were "shocked and dumbfounded" by his arrest, said Robert Chase, the executive director of Intersections International. Enright volunteered with the nonprofit group, and it partially funded his trip in the spring to Afghanistan.
As part of his thesis, Enright shot a film on American soldiers serving there, Chase said.
Authorities are reviewing multiple journals Enright had on him at the time of his arrest to see if they contain evidence that he had recently undergone some kind of mental or emotional change, a source at New York's City Hall told CNN Thursday.
The notebooks are filled with writing, some if it illegible, the source said.
Authorities are reviewing Enright's journals for signs that had post-traumatic stress disorder or other emotional stress, the City Hall source said.
The goal of Intersections International, based in New York, is to promote peace across faith and racial boundaries, according to its website.
"Everyone was shocked and dumbfounded because of the nature of the crime and because of our experience with him here," Chase said. "It is sadly ironic."
He said Enright volunteered on Intersections International's Veteran-Civilian Dialogue program, which addresses trauma faced by returning veterans and encourages them to share their stories with civilians and each other.
"He was intrigued by the concept and started participating and then volunteering. Enright became involved in the work we do -- building bridges across race, culture and religion and forging common ground for reconciliation and peace," Chase said.
"The whole thing is unfathomable," he said. "He's a good guy. His work has been responsible. He's been diligent and hardworking."
Meanwhile, the cab driver, Ahmed Sharif, called for New Yorkers to "love and respect" one another. "This is a city of all colors, races, religions," he told a group of supporters outside City Hall.
But Sharif said he was targeted because of his faith. "Of course, it was because of my religion," he said, noting that the passenger "made some jokes about Ramadan," the Muslim holy month of fasting, and attacked him after asking him if he was Muslim.
"Sometime I feel very lonely and unsafe," said Sharif, who has lived in New York for more than 25 years and has been driving a taxi for 15 of them.
After the news conference, Sharif, his wife and four children met with New York Mayor Michael Bloomberg, who gave them gifts that included NYPD hats and "I Love New York" T-shirts.
"No matter how wonderful this country and city is, some people act disgracefully," Bloomberg told reporters as Sharif stood by his side. "Fortunately, this is rare, but one time is one time too many. This is America, this is New York; what a disgrace. His wife told me they came to America to make a better life for their wonderful kids."
Enright is facing charges of second-degree attempted murder as a hate crime, second-degree assault as a hate crime, second-degree aggravated harassment as a hate crime, and fourth-degree criminal possession of a weapon, said New York police Detective Mark Nell.
Authorities said Enright was intoxicated at the time of the incident; they found an empty bottle of scotch in a backpack he had with him.
When Enright first got into Sharif's cab Tuesday night, the conversation was cordial, said Bhairavi Desai, executive director of the Taxi Workers Alliance.
The suspect "started out friendly, asking Mr. Sharif about where he was from, how long he had been in America, if he was Muslim and if he was observing fast during Ramadan," Desai said.
Then, after a few minutes of silence, Desai said Enright started cursing at Sharif and shouted "Assalamu Alaikum, consider this a checkpoint," before slashing him.
"Assalamu Alaikum" is an Arabic greeting that means "peace be upon you."
The taxi workers alliance said Sharif, 43, a practicing Muslim originally from Bangladesh, was slashed across the neck, face, shoulder and hand.
Bleeding profusely, Sharif escaped and flagged down a police officer, who arrested Enright, Desai said.
New York Gov. David Paterson condemned the attack. "We cannot and will not allow bias and ignorance to infect our communities and deny our hardworking, innocent residents the respect they deserve," he said in a statement.
The attack occurs amid public debate over plans to build an Islamic cultural center and mosque to be called Park51 two blocks from the site of the September 11, 2001, terrorist attacks on the World Trade Center.
"Right now, the public sentiment is very serious because of the ground zero mosque debate," Sharif said in a statement.
Paterson said the potential for such violence is one of the reasons "I have called publicly for a respectful and unifying conversation about the Park51 project," he said. "I continue to offer my assistance for an open dialogue that I believe will help to bring New Yorkers together."
CNN's Deborah Feyerick, Jason Kessler, Meg Miller, Christina Romano and Jesse Solomon contributed to this report.