A four-week investigation found no evidence that Rep. Jim Gibbons assaulted a cocktail waitress at a parking garage one rainy night in October, Las Vegas police said Thursday.

The Metropolitan Police Department announced the findings after wrapping up the investigation and submitting the results to the district attorney's office. Police recommended that no charges be filed against Gibbons, now governor-elect, because detectives had found "no evidence to support the charge of battery."

Detectives interviewed 44 people and spent more than 770 hours working on the investigation, which was prompted by accusations from Chrissy Mazzeo that Gibbons grabbed and threatened her Oct. 13, after a night of drinking at McCormick & Schmick's on Flamingo Road.

Gibbons said he grabbed Mazzeo's arm only to keep her from falling after she tripped.

Some Gibbons supporters claimed Mazzeo's accusations were nothing but a political ploy intended to hurt the Republican's run for governor against Democrat Dina Titus.

Others criticized authorities' handling of the investigation, in particular Sheriff Bill Young's call to Gibbons to tell him of the allegations, and the surfacing of surveillance video from the garage 12 days after police said they were told cameras were not recording the night of the incident.

Gibbons' attorney, Don Campbell, said the police findings support what Gibbons has been saying all along -- that nothing inappropriate happened between him and Mazzeo.

"This whole matter was a figment of someone's imagination," Campbell said.

He said it was unfortunate that so many police resources went toward investigating an allegation that never had any evidence to support it.

"You've got the most expensive misdemeanor investigation in the history of the Western World," Campbell said. "And it has substantiated what Governor-elect Gibbons has said from day one. He was never in that garage, and he never assaulted Ms. Mazzeo."

Gibbons was attending the Republican Governors Association conference in Miami and could not be reached Thursday night, said Brent Boynton, his communications director.

"All along he said he never did anything improper that night, either inside or outside the restaurant," Boynton said. "He knew there were no legitimate charges to be filed, so he won't be surprised by this."

Mazzeo's lawyer, Richard Wright, did not return a phone call seeking comment.

Reached Thursday, Mazzeo referred questions to Wright.

District Attorney David Roger said he received some of the case file by e-mail Thursday and expected to receive two large binders from police this morning.

He said he would personally conduct a comprehensive review of the case to determine if any charges are warranted.

"I expect it will take me several weeks to make a decision on the case," Roger said. "I removed myself from the investigation so I could take a fresh, objective look at the evidence presented to me."

That evidence includes interviews and police reviews of surveillance video tapes from "all possible sources," according to police.

Mazzeo told police she left the restaurant after a night of drinking and encountered Gibbons outside the front door. She said Gibbons was walking her to her vehicle when he grabbed her, shoved her against a wall and threatened to rape her.

Mazzeo called police. But the next day she withdrew her complaint because it involved a high-profile politician and she didn't want a media circus, according to police reports.

At news conferences in the following weeks, Mazzeo said Pennie Puhek, a friend who was with her the night of the incident, relayed threats and bribe offers from the Gibbons camp to try to get her to recant her story. Puhek denied those claims and said Mazzeo needed "professional help."

Wright also criticized the police department's handling of the case, especially Young's call to Gibbons on Oct. 14 to tell him of the allegation. He also questioned investigators' objectivity. Young, a Republican, had endorsed Gibbons for governor.

The lawyer had asked for another agency to investigate.

Police reopened the case Oct. 30. From that point on, Young said, he isolated himself from the investigation. He found out that the investigation was finished through an e-mail news flash Thursday, he said.

Young defended the work of his detectives, saying they handled the investigation with credibility and professionalism.

"They are not tainted by me or politics or anything," he said.