Tape showed Zimmerman's anger over black man's beating

Last year in September, Zimmerman wrote an e-mail to Sanford Police Chief Bill Lee saying, "In the past, I have not had a positive perspective of Sanford Police Department, due primarily to the Sherman Ware incident."

A video from the night of Ware's beating showed Justin Collison hitting the young man. Collison ended up pleading guilty to misdemeanor battery

Zimmerman's outrage over the incident was clear at the public meeting the previous January.

"I would just like to state that the law is written in black and white. It should not and cannot be enforced in the gray for those that are in the thin blue line," he said at the hearing. CNN obtained a recording this week.

He mentioned Brian Tooley, who was Sanford's police chief at the time of the Ware incident. "I'd like to know what action the commission intends on making in order to repeal Mr. Tooley's pension. I'm not asking you to repeal his pension. I believe that he's already forfeited his pension by his illegal cover-up and corruption and what happened in his department."

While Zimmerman is not heard specifically mentioning Ware in the recording, the official minutes from the hearing state that citizen demands included "a full review of the Sherman Ware cover-ups on behalf of" Sanford police.

Public outcries of police misconduct forced Tooley into early retirement. He was not charged with illegal activity.

Despite his previous frustration with police, the September e-mail included thanks to Lee and praise for the department's "professionalism."

The e-mail, eight months after the public meeting, shows a significant shift in Zimmerman's relationship with police, months before officers responded to the Trayvon Martin shooting.

However, a spokesperson for Lee said in a e-mail to CNN that the police chief "has never met Mr. Zimmerman and does not know him."

"The email Chief Lee received in 2011 was not unique among the numerous complimentary emails Chief Lee has received from Sanford residents," Sara Brady wrote. "As is his practice, Chief Lee responded to a positive comment from a citizen. Based on comments that Mr. Zimmerman is reported to have made in a public forum before Chief Lee was hired, it is not likely that Mr. Zimmerman would have endeared himself to members of the police department."

Zimmerman, a neighborhood watch volunteer, is charged with second-degree murder in the death, which sparked nationwide protests and inflamed public passions over race relations and gun control.

Critics of the case have questioned his relationship with police, noting that Zimmerman worked closely with officers as part of his work with the neighborhood watch program he started.

The January 8, 2011, recording from the meeting at Sanford's City Hall is a reminder that the relationship wasn't always positive.

"I also have had the opportunity to take ride-alongs with the city of Sanford Police Department and what I saw was disgusting," Zimmerman said at the time. "The officer showed me his favorite hiding spots for taking naps. ... He took two lunch breaks and attended a going-away party for one of his fellow officers."

Sanford Police Capt. Robert O'Connor told CNN that the department does not have specific details about when Zimmerman rode with police or whom he rode with, "if in fact he ever did ride with SPD."

In the September 18, 2011, e-mail, obtained by CNN after a records request, Zimmerman said he had "a completely new perspective" after working closely with the department's community volunteer coordinator.

He praised the volunteer coordinator's quick responses to e-mails and phone calls, saying she went "above and beyond to help launch a neighborhood watch" and calling her "a testament to the highest level of professionalism of (the chief's) administration."

"I have high hopes for, and restored faith in your administration and the Sanford Police Department in its entirety," he wrote.

Sanford interim Police Chief Richard Myers declined comment to CNN, but told the Miami Herald newspaper in a written statement, "Based upon the questions being posed, it would be inappropriate for any of us to speculate or conclude anything gleaned from the recording or any e-mail documents.

"Neither the city manager nor the interim police chief were with the City of Sanford at the time the recording was made, and neither were here during the tenure of the former chief cited in one of the questions," the statement said. "As a police chief I embrace the notion that transparency helps build public trust, but in this case, the need to preserve the sanctity of a criminal prosecution for both the prosecutor and the defense requires us to eschew making any comments that could taint the process."

Documents released last week showed a cordial relationship between Zimmerman and the police.

Beginning in August 2011, Zimmerman exchanged e-mails with the Sanford police department at least three times, the documents show. A rash of burglaries that began in July prompted the watch captain to ask the police department to host a neighborhood watch presentation for members of the community.

Zimmerman's e-mails with Sanford police show a pleasant, even friendly, relationship. In an e-mail dated September 19, Sanford police volunteer coordinator Wendy Dorival thanked Zimmerman for his "kind words" sent to the chief. He responded, "It was with great pleasure that I sent that e-mail, you deserve the recognition!"

Police records indicate that five burglaries were documented in the neighborhood where Zimmerman lived in less than three months, starting in mid-July.

Five months before the Martin shooting, at the neighborhood watch meeting on September 22, Sanford police distributed contact cards and hosted a presentation on crime-prevention and security measures, according to the documents. Some of the fliers distributed read, "Report suspicious persons ... activities ... or vehicles." Another reads, "Know your neighbor" -- going on to issue advice on how to "profile" your neighborhood block.

Zimmerman was charged with second-degree murder in April.