In a Monday letter to the Tacoma City Council, City Manager Ray Corpuz announced his intention to retire after the Washington Association of Sheriffs and Police Chiefs concludes its investigation into the Brame case, releases its final report and after city leaders respond to the findings.

Police Chief David Brame shot his estranged wife in the head April 26 in a Gig Harbor parking lot. He then turned the gun on himself and died later that day. Crystal Brame died a week later.

In the letter, Corpuz identified many people who endorsed and supported Brame’s appointment to chief, but acknowledged no one could predict “this selfish and irrational act.”

“Who should be asked to shoulder the burden of blame?” Corpuz asked. “He, and only he, is responsible and accountable for that senseless crime.”

Corpuz’s letter also focused on the need to prevent a similar tragedy in the future. He said he would continue to be supportive and cooperative with the WASPC investigation, including responding to the findings.

“It is painfully clear that our current appointment process does not always provide and complete and accurate picture,” Corpuz said. “This system needs changing, and we are capable of making those improvements. Some changes should wait for the results of the investigation, while others should start immediately.”

Corpuz has served as city manager for more than 13 years. He has held several government positions throughout his career, including as the government relations director for Pierce County government and director of intergovernmental affairs for Tacoma.

In another development, Washington’s top state and federal law enforcement officials announced Monday a joint investigation into all aspects of the murder-suicide of the Brames.

“We will conduct a rigorous, independent and thorough investigation into all aspects of this troubling case,” state Attorney General Christine Gregoire said at a news conference with Washington State Patrol Chief Ronal Serpas; John McKay, U.S. attorney for Western Washington; and Charles Mandingo, special agent in charge of the Seattle FBI office.