INDIANAPOLIS -- Two City-County councilors on Thursday joined those calling for the firing of Indianapolis Public Safety Director Frank Straub following several high-profile embarrassments for police.

Councilors Brian Mahern and Maggie Lewis, both Democrats, said that Straub impeded the investigation into Officer David Bisard -- who authorities said was driving drunk when he hit a group of motorcyclists, killing one -- by publicly saying there was no evidence of intoxication at the scene.

"This was premature as the investigation had not been concluded and, furthermore, it potentially undermines the prosecution's case," Mahern said. "He must go."

At Thursday's news conference, Mahern, Lewis and Melina Kennedy, a Democratic candidate for mayor, also called for an expanded independent investigation of Indianapolis police and voiced support for a bipartisan commission to examine policies and procedures with the Indianapolis Metropolitan Police Department.

"The public has lost confidence and is still seeking accountability and the public thirsts for leadership," Mahern said. "Until we see Director Straub removed, we'll have a very difficult moving forward."

Republican Council President Ryan Vaughn outlined a similar proposal for a Public Safety Integrity Commission on Wednesday, but told 6News' Kara Kenney he doesn't agree with calls to fire Straub.

"No one in my caucus and most of the people I talk to on the street and in the community, no one believes it's productive to continue to echo these hollow calls for resignation for a guy who is as well credentialed as Director Straub," he said.

A spokesman for Mayor Greg Ballard said the firing of Straub is unlikely.

"Only the mayor can make that decision, but he's made it very clear he has the utmost confidence in him and he shouldn't be fired," said Robert Vane. "The mayor's trying to heal the city while people are making political squealings."

In response to calls for his removal, Straub's office released a statement saying, "Director Straub is committed to making the Department of Public Safety and the IMPD the best in the nation, and will continue leading the department toward that goal."

At Monday night's City-County Council meeting, protesters from the Baptist Ministers Alliance called for Straub's firing, blaming him for low morale within the department, which they say may have spurred some officers to bad behavior.

The City-County Council is expected to discuss the possible creation of a bipartisan commission to review IMPD policies at its Sept. 20 meeting.