Cunningham, 35, hasn't been seen or heard from since, his family and police have said, sparking a $10,000 reward offered by the family in partnership with Crime Stoppers Greater Atlanta for information leading to an arrest and indictment for his disappearance.
O'Connor said that the case was extremely unusual because they've been able to locate all of Cunningham's belongings, including his wallet, cell phone, vehicle keys and other important cards and documents.
A Harvard-educated doctor, Cunningham is a highly regarded epidemiologist at the CDC, having risen through the ranks to become a team leader in the US Public Health Service Commissioned Corps. Cunningham's dog, Beau, was also at home.
On that morning, O'Connor said, Cunningham went to work after calling his sister. They say there is no evidence of foul play.More news: British police sift through rubble at scene of fatal blast
Atlanta police say they checked Timothy Cunningham's personal credit cards to see if they were being used, as well as phone records.
"He would not be the type of person, if you kidnaped him and held him, he could give you some horrific virus that could be a real problem for all the rest of us", O'Connor said. Shortly after being formally informed he would not receive the promotion, he reportedly told his managers he felt ill and left early.
Cunningham graduated from Morehouse College and earned advanced degrees from Harvard.
In addition, Internet rumors about Cunningham being a whistle-blower who had cautioned the public about the flu shot being responsible for this year's deadly flu season have been touted as a possible reason for his disappearance, a claim that his father, Terrell Cunningham disputed as false to CNN.
The parents revealed they received unusual texts and calls from Timothy the night prior while speaking to Today about their contact with him before. "We just want you back in our arms", she said. The mother said she saw the message later as her phone was on silent mode.
Though theories may start running rampant, Cunningham's parents have come up short as to why their son has gone missing. O'Connor said Cunningham's house seemed secured other than two windows on the upper level which were open. "I wish I had that opportunity to answer that text", she said.