The role of race in the controversial arrest of Harvard professor Henry Louis Gates Jr. became more difficult to untangle Monday with the release of the tape of the emergency call that brought Cambridge, Mass., police to his door. The tape revealed that the woman who reported seeing two men trying to break into a house did not know their race. When pressed twice by the emergency dispatcher to identify the men by race, Lucia Whalen said: 'Um, well there were two larger men. One looked kind of Hispanic, but I'm not really sure. And the other one entered and I didn't see what he looked like at all.' Nearly all of the facts about what happened before Gates and Sgt. James Crowley met at the scene of a possible break-in are now known. The stories diverge when the two men are alone together in the house, navigating what both have since called an 'unfortunate' encounter. That encounter exploded into a national incident, one that has since prompted President Barack Obama to discuss the fraught relationship between minorities and police and to invite both Gates and Crowley to the White House for a beer. When Whalen made the call, she told the dispatcher that she and another neighbor saw two men with two suitcases pressing on the front door of a yellow wood-frame house but that she was not sure they were trying to break in. At one point she even entertained the possibility that they lived there. Whalen, who works at Harvard University's alumni magazine a few feet from Gates's house, has been vilified in online comments and blogs as a racist 'white woman' who saw 'two black men' trying to enter a home and assumed they were breaking and entering, but she had declined to comment until Sunday, when, through her attorney, she issued a statement knocking down a line in the police report filed after the incident. It describes Whalen telling Crowley, who responded to her call, that she saw 'two black men with backpacks.' The lawyer, Wendy J. Murphy, told CNN on Monday that Whalen did not identify the men by race at any point. Cambridge police officials, who released the tape of the 911 call, have said they stand by the report. According to the police report, Crowley spoke briefly to Whalen before turning to the yellow house, where he saw Gates inside. It is at this point, said psychologists who study law enforcement and race, that racial attitudes apparently entered the exchange between Gates, an African American, and Crowley, who is white. Gates has said he was immediately taken aback by Crowley's tone. 'It was clear that I was in danger,' Gates has said, describing his reaction to Crowley coming to his door and asking that he step outside. Gates refused to leave his home and instead walked to his kitchen to get his identification. 'I weigh 150 pounds and I'm 5-7. I'm going to give flak to a big white guy with a gun? I might woof later, but I won't woof then,' Gates said in describing his approach to the encounter. Crowley described Gates's reaction to his request as belligerent, and the officer is heard on radio transmissions saying, 'I'm up with a gentleman who says he resides here but is uncooperative.' Crowley never mentions Gates's race on the radio calls and the professor's voice is not audible, though the officer described Gates as 'loud and tumultuous' in his police report. Lorie Fridell, an associate professor of criminology at the University of South Florida, said the two men's divergent stories are borne out by research that has been conducted into the 'implicit biases that work below the conscious level in many of us, including those of us who want to be without prejudice.' 'There's this backdrop to the interaction that is based on the negative history of the police and minorities,' said Fridell, who consults with police departments and provides command-level training on racial profiling. 'For some police, when (officers) go into an interaction with a person of color, they may be expecting less deference or may be expecting from that person more aggressiveness. If the officer is expecting that, he or she might become more forceful in expectation, and I could see the possibility of a downward spiral.' On the other hand, many African Americans are taught to show respect to police out of fear for 'survival' -- even when they feel they are being mistreated -- because they are stereotyped as 'violent,' said Paul Butler, a professor of law at George Washington University and former federal prosecutor. 'There is a history of assertive African Americans having bad encounters with police,' he said. Staff writer Cheryl W. Thompson contributed to this report. 