But the union chief said he believes only a small fraction of the officers will wind up being deserters. "We know there were officers who had to make critical decisions about what to do with their families," Benelli said.
Riley said some officers lost their homes and some are looking for their families, but others "simply left because they said they could not deal with the catastrophe."
Before Katrina hit, Compass already had his hands full with an understaffed police department and a skyrocketing murder rate, even as the rate dropped dramatically in other cities.
Despite more than 10 years of reform efforts dating to before Compass took office, police were dogged by allegations of brutality and corruption. Several studies indicated that the public's reluctance to cooperate with police was a factor in the city's crime problem.
Before Katrina, New Orleans had 3.14 officers per 1,000 residents _ less than half the rate in Washington, D.C.
Also on Tuesday, the state Health Department reported that Katrina's death toll in Louisiana stood at 885, up from 841 on Friday.
Tuesday marked the second day of the official reopening of New Orleans, which had been pushed back last week when Hurricane Rita threatened. Nagin welcomed residents back to the Algiers neighborhood on Monday but imposed a curfew and warned of limited services.
Nagin also invited business owners in the central business district, the French Quarter and the Uptown section to inspect their property and clean up. But he gave no timetable for reopening those parts of the city to residents.
Associated Press Writers Mary Foster and Michelle Roberts in New Orleans, and Amy Forliti in Baton Rouge contributed to this report.