Updated at 4:28 pm

At a press conference this morning, Boston Police Commissioner William Evans announced that he is retiring, and Mayor Marty Walsh announced that William Gross will succeed him as the next commissioner.

Evans is stepping down to become the executive director of Public Safety at Boston College in August. He became interim commissioner in late 2013 and accepted the permanent role when Mayor Walsh came into office the following year.

"It was one of the most, if not the most, important decisions I had to make," said Walsh of appointing Evans. "It was the right decision."

Evans has been with the department for 38 years, and he said, "I never dreamed of the day I'd be up here as commissioner." His retirement was previously reported by a local broadcaster a month ago but at the time, the commissioner and mayor adamantly denied the story.

Gross, who has been serving as the superintendent-in-chief of police since 2014, will be the city's first African-American police commissioner. He thanked Walsh, his family, and the city of Boston for their support as he takes the next step in his career. He also thanked Evans for his service and leadership style.

"He took that true leadership style and he applied it," Gross said of Evans. "He ensured that it resonated in the rest of the department."

Gross also said he sees Boston as a positive model for other cities trying to move forward after tensions between police and communities of color. The new commissioner says he plans to focus on combating youth violence in the city.

Members of the Massachusetts Association of Minority Law Enforcement Officers praised the selection. Larry Ellison, the group's president, called the move a "big deal" and noted that Boston hired its first black police officer, Horatio Homer, more than a century ago.

"So we are almost 100 years since his appointment to now we have our first Black police commissioner so its been a long time coming," said Ellision, who graduated from the police academy with Gross.