DENVER -- A memorial service is planned Thursday for an Adams County deputy district attorney who was shot while walking across his back yard on his way home after work.

Denver police said they believe the person who ambushed Sean May, 37, was waiting in the yard and shot May in the head and abdomen on Aug. 27.

An intense search around his northwest Denver home yielded no trace of the gunman or the weapon used.

No motive has been released, and it is unclear whether the shooting was related to May's work. As chief deputy district attorney in Adams and Broomfield counties, May handled cases involving the child victims' unit and murder trials.

He worked for the 17th Judicial District Attorney's Office for seven years.

May's memorial service will be held at 11 a.m. at the the Temple Hoyne Buell Theatre at the Denver Performing Arts Complex.

Gov. Bill Ritter on Wednesday ordered U.S. and Colorado flags lowered to half-staff across the state in honor of May.

The family has requested that, instead of flowers, donations be made to the Sean May Memorial Fund at any Wells Fargo bank. Make checks payable to the "Sean May Memorial Account."

“Sean was one of the great ones, he truly was. He was one of the fantastic prosecutors and a fantastic friend,” said Ted Tow, a former Adams County prosecutor who worked with May in the child victim unit. “It’s an extremely difficult docket, but Sean had an incredible ability to connect with kids.”

Tow said that even though May knew the risks he loved being a prosecutor

“Because it was doing the right thing,” said Tow. ”It was helping society. It was keeping the community safe.”

While Denver police pass out flyers asking the community for information, May’s friends are just trying to wrap their heads around the senseless crime.

His wife, Corin, is expecting their first child, and Tow said May couldn’t have happier.

“One of the last things he told me when we talked to weeks ago was how blessed he was, how lucky he was,” said Tow.

Donations can also be made online at seanmaymemorial.com.

Anyone who has information about the shooting is asked to contact Denver Crime Stoppers at 720-913-7867 or Denver police.