A fresh revelation about the mishandling of evidence in a fatal crash involving an Indianapolis police officer has renewed suspicions about a possible cover-up as well as concerns about a culture of corruption within the department.

The development prompted the city's police chief, Paul Ciesielski, to step down Tuesday, and left Public Safety Director Frank Straub being grilled by a city-county committee Wednesday night. It also brought back claims of a cover-up that first surfaced shortly after the crash, when prosecutors announced a blood test showed Officer David Bisard had a blood-alcohol level of 0.19 more than two hours after the accident.

Many were incredulous that neither police at the scene nor the medical personnel who drew the blood and evaluated Bisard for injuries realized he was drunk. Some also questioned why Bisard was taken to a clinic used by police, rather than to a hospital — a move that resulted in the first blood test being thrown out because it was improperly administered by someone not legally certified to take the sample.

The latest mistake happened in November, when prosecutors say a vial of blood belonging to Bisard was taken from the main police property room, where the sample was refrigerated, to the annex, where it was not. Prosecutors had hoped to use the blood to show Bisard was drunk when he plowed his squad car into two motorcycles stopped at a red light in August 2010, killing 30-year-old Eric Wells and injuring two others.

Bisard's attorney, John Kautzman, said Wednesday that the blood sample actually could have helped clear his client.

Bisard's case isn't the only problem for the department. It had a string of issues when Mayor Greg Ballard in 2009 plucked Straub from a seven-year stint as police commissioner of White Plains, N.Y. In two years before Straub was hired, Indianapolis officers had been accused of trafficking drugs, arson, running a prostitution ring and taking bribes.

Since Straub's arrival, he has been dogged by trouble within the department, including claims of excessive force and the arrests of several officers on criminal charges. Straub has claimed the incidents were coming to light because he had taken a hard stand against corruption.

The city-county council's criminal justice committee took up Straub's reappointment Wednesday but put off a vote until later. It could either recommend his reappointment to the full council or issue no recommendation, an effective no-confidence vote.

Straub didn't return phone calls seeking comment Wednesday. At a news conference Tuesday, he assailed what he described as a police culture that had tolerated bad behavior for decades. However, he also emphasized that most of the 1,600 men and women on the force were hard-working, decent people.

A judge last week had given prosecutors permission to test a second blood sample in Bisard's case — the one prosecutors say they can't use because it was mishandled and removed from refrigeration.

Crash survivor Mary Mills said the problems in the case have led her to doubt the police force.

"I know there are good police officers out there. I know there are. I just haven't run across one in this case," she said at a news conference Wednesday.

Aaron Wells, whose son was killed in the crash, was skeptical the removal was just an accident.

"People make mistakes, we're all human," he told The Associated Press. "But it would have been almost impossible to make that many mistakes without there being an effort to do so."

A criminologist who has written several books about police culture said it isn't rare for officers to cover for one another's mistakes, though he said he couldn't speak specifically about Indianapolis.

"People in any workplace will always cover for each other against outsiders," said John Crank, a professor at the University of Nebraska at Omaha. "It's easy to develop an internal rationality for covering for officers and believing that the officer isn't that bad."

Bisard is still awaiting trial on reckless homicide and other charges. An internal police investigation found he was driving at 73 mph in a 40 mph zone while using a laptop when the crash happened.

Kautzman, his attorney, said it was pointless to speculate on whether corruption was involved without some sort of investigation.

The local police union denied Straub's claims that the department is filled with corruption, saying Straub was "intentionally misleading" in the picture he painted.

"It will be important in the days and weeks ahead to allow this new investigation to be completed and not to rush to judgment as others in leadership positions have done. .... The history of our department does not reveal a department rife with corruption and ineptitude, but of unselfish acts of heroism, sacrifice, and dedication," the local Fraternal Order of Police said in a statement issued Wednesday.

Marc Lotter, a spokesman for Ballard said the department needs to continue with reforms in the areas of hiring, training and promotion initiated under Straub.

"That is first step in rebuilding that public trust," Lotter said.