A former city of Atlanta employee was sentenced to prison Monday in the ongoing public corruption investigation into alleged bribes paid for government contracts.

The case, according to prosecutors, involved a “shut up” message on a concrete block thrown through a window and dead rats left on the porch of the home of a federal witness.

Shandarrick Barnes, 41, was sentenced to three years and one month in prison for obstructing justice in the federal corruption investigation involving city government, U.S. Attorney Byung J. “BJay” Pak said in a news release. Pak said Barnes admitted he threw a concrete block through the window of E.R. Mitchell's home and put rats on his porch and elsewhere, hoping to stop his cooperation with federal law enforcement.

“Barnes thought he could thwart the City of Atlanta corruption investigation by throwing a concrete block through a federal witness' window,” Pak said in the news release. “Instead, investigators became even more resolute in their efforts to root out a pay-to-play system that undermines the public's trust in government.”

David LeValley, special agent in charge of FBI Atlanta, added in the release that the bureau wanted to “send a strong message to anyone who would attempt to subvert law enforcement agents and officers in their search for the truth.”

“Witness intimidation is a serious crime, and today's sentence shows the consequences of obstructing a federal investigation,” said Thomas Holloman, special agent in charge, IRS Criminal Investigation. “This investigation is ongoing and we encourage anyone with any information to come forward without fear of reprisal or intimidation.”

Attorney William Morrison of the Morrison Firm in Atlanta defended Barnes. Morrison said the sentence could have been worse if he had not managed to reach an agreement with prosecutors to bump the charge down from interfering with a bribery investigation to interfering with a tax investigation. “We were very pleased with the sentence today,” Morrison said. “It was much lower than it could have been.”

The release noted that Barnes is to receive credit for five months' time spent behind bars, and Morrison said Barnes also will receive credit for another eight months he spent in federal prison.

Morrison said Barnes formerly worked for Mitzi Bickers, a onetime city of Atlanta executive who was arraigned last week on 11 federal charges including conspiring to commit bribery, wire fraud, money-laundering, federal obstruction and tax fraud. Bickers was indicted by a federal grand jury on March 27, 2018. Barnes also worked for the city of Atlanta, his attorney said.

In late July 2015, special agents with IRS and the FBI approached E.R. Mitchell, Jr. for an interview relating to an ongoing investigation into corruption in city government. During the meeting, agents discussed corruption allegations as well as potential tax improprieties, according to authorities.

Shortly after the IRS and FBI agents approached and interviewed him, Mitchell informed others that federal law enforcement had spoken with him and was asking questions, according to Pak, who said Mitchell was interviewed on Sept. 2, 2015, by the U.S. Attorney's Office and federal agents and confessed to regularly paying “upfront money” for city contracts. On Sept. 8, 2015, Mitchell returned to the office and completed a second debriefing with prosecutors and agents, Pak said.

On Sept. 11, 2015, at approximately 5:45 a.m., Barnes threw a concrete block with the words, “ER, keep your mouth shut!” written on the side through a plate-glass window in Mitchell's home, according to Pak's office. When Mitchell went outside to see who had thrown the block, he allegedly saw that dead rats had been placed on his porch, on his car and in his mailbox. The police and FBI investigated and found security video footage from the subdivision. The video showed a car that appeared to match Barnes' vehicle left the area minutes after the block was thrown through the front window, Pak said.

On July 13 and Aug. 17, 2016, according to Pak, Barnes was interviewed by the FBI and IRS and admitted throwing the concrete block through Mitchell's window. Barnes specifically acknowledged that he was aware of the investigation into Mitchell and others, and that agents had asked about Mitchell's taxes as well as payments Mitchell made to businesses associated with Barnes' employer. He was well aware that Mitchell was actively cooperating with agents, Pak said. He said he was livid, and his decision to throw the brick through Mitchell's window was motivated by his desire to hinder Mitchell's communication with agents, according to Pak. He said he felt that Mitchell's communications to federal law enforcement would negatively affect his employer's businesses and would be detrimental to obtaining other business that he and others were actively seeking at that time, Pak said.