Philadelphia District Attorney Seth Williams announced some changes in the department Monday.
First Assistant District Attorney Ed McCann has resigned.
He's been with the DA's office for 26 years and in addition to being First Assistant, McCann was Chief of the Homicide Unit.
In making the announcement, Williams called McCann a trusted advisor and a terrific prosecutor.
"The City of Philadelphia is a safer place because of the extraordinary service, hard work and commitment of Ed McCann," Williams said in a statement.
Williams announced that Deputy DA George Mosee will take over the First Assistant job.
He also announced the new position of Chief of Staff, General Counsel and Chief Integrity Officer will be held by Kathleen Martin.
"It is a pleasure to make today's announcement because all of us here at the Philadelphia District Attorney's Office want to be effective and do our jobs with the highest levels of service that we can provide. We also want to be the best team that we can for the people of Philadelphia," Seth Williams said.