TOPEKA, Kan. (AP) -- Shawnee County sheriff's deputies continue investigating the Dec. 16 killings of two Topeka police officers even though the assailant was shot to death the following day.

Sheriff Herman Jones has asked the county commission for overtime expenses for the investigation into the deaths of police Officer Jeff Atherly and Cpl. David Gogian.

The two were shot to death while checking possible drug activity outside a Topeka supermarket. Their killer, 22-year-old David Tiscareno, was shot and killed by law enforcement officers Dec. 17.

Jones told The Topeka Capital-Journal (http://bit.ly/12Jjk5V ) that his office still had some people to interview.

The sheriff told the Shawnee County Commission his office would need $8,000 from its 2012 budget to help pay overtime in 2013 for the investigation.