Montgomery County Police Chief Charles Moose (search), who led the three-week hunt for the Washington-area sniper, resigned Wednesday after a clash with county politicians over his upcoming book on the investigation.

Moose, 49, said in a statement that he had worked to make the county a "safe and secure place to live" but that it was time "to move on and explore other paths in life."

His book, Three Weeks in October, is scheduled for release in October, one year after the sniper attacks.

In March, the county ethics commission ordered him to drop the project and barred him from serving as a consultant on a movie about the sniper case, saying a county employee may not profit on the side from his official duties.

The commission also said the book could undermine the prosecution in the sniper case by catering to "the public's thirst for all of those `inside' details." The defendants' attorneys also object to the book, saying it could taint possible jurors.

Moose appealed in state court and also filed a federal lawsuit claiming his free speech rights were being violated.

County Executive Douglas Duncan, who backed the police chief's desire to write the book, said Wednesday that Moose told him he felt that he had to make a choice between remaining as chief and completing the book.

"He felt this was the best for everyone involved," Duncan said. "It would let him do the book and remove the cloud over it.

"The opportunities that were presented by the book were too good to pass up."

The letter said Moose's resignation would be effective June 28.

He has been on active duty recently with a military police unit of the National Guard (search) and had been posted at Andrews Air Force Base. Bruce Romer, chief administrative officer for Montgomery County, said Moose was not expected to return before his resignation takes effect.

Moose's department was the headquarters for federal, state and local investigators tracking the sniper, and he became a daily fixture on national television during the investigation, giving news conferences several times a day. For many, he was a reassuring figure, especially when he let down his tough exterior to shed a tear for a 13-year-old boy shot and wounded at school.

Authorities arrested John Allen Muhammad (search) and teenager Lee Boyd Malvo (search) in the sniper attacks. The two have been linked to 20 shootings, 13 fatal, in Virginia, Maryland, Georgia, Alabama, Louisiana and the District of Columbia.