A top aide to Mayor Marty Walsh on Thursday afternoon announced three additional appointments. In an email to City Hall workers, Walsh chief of staff Daniel Koh thanked them for their patience and said he would keep them informed about new hires and promotions.

According to the email, which was obtained by the Reporter, Justin Holmes, a Dorchester native, is the interim chief information officer. Holmes, who served as chief of staff to Maureen Feeney when she was the City Council president, was director of constituent engagement under Mayor Thomas Menino.

“Justin is one of a kind,” Feeney, who is now the city clerk, said in a 2010 Reporter profile of Holmes. “His passion for everything he does is backed up by his intellect and his ability to see a problem or a crisis and very calmly work through that.”

Michael Dennehy, another hire with Dorchester ties, has been appointed interim commissioner of public works, after serving as assistant superintendent.

Jim Gillooly, a deputy commissioner at the Transportation Department, has been appointed interim commissioner.

The three appointments went into effect immediately.

“There will be more announcements coming soon, but if you have any questions at all, please feel free to contact me,” Koh wrote in the email. “My door is always open to any of you.”

Earlier in the day at Boston Police headquarters, Walsh rolled out the appointments of William Evans as the police commissioner, and William Gross as superintendent-in-chief. Evans started serving as interim police commissioner after Ed Davis stepped down.

Gross, who has spent 28 years in the department, is the first African-American to hold the job of superintendent-in-chief. Gross has worked in the gang unit, the drug control unit and the school police unit. He was promoted to superintendent/night commander in 2012.

"I’ve known Chief Gross for many years, going back to the early days of my career as a state representative in Dorchester,” Walsh said in a statement. “I know his deep ties to our community and broad experience give him a uniquely qualified perspective on addressing violence in Boston’s neighborhoods.”