DAYTON, Ohio (AP) _ Four people were charged Monday with murder in what police labeled a 36- hour ''joy killing'' spree that left five people dead and four wounded.

The shootings began Thursday ''as robberies, but it became easier and we think it turned into joy killing,'' police Sgt. George Hammann said. The assailants ''were like a shark - once they tasted blood they couldn't stop.''

Two adults and two juveniles were charged with aggravated murder and aggravated robbery, said Montgomery County Prosecutor Matthias Heck.

Heck said he would seek the death penalty against Marvellous Keene, 19, and Heather Matthews, 20. He said he would seek to try Demarcus Smith, 17, and Laura Taylor, 16, as adults, but can't seek the death penalty because of their ages. All four are from Dayton.

The younger two would face a maximum penalty of 25 years in prison if tried as adults and convicted.

Court appearances were not immediately scheduled.

The spree began Thursday, when Danita Gulette, 18, of Dayton was fatally shot at a pay telephone in an alley. Later, Jeffrey Wright, 28, of Dayton was shot four times outside a house. He was not seriously injured, police said.

On Friday, Richmond Maddox, 19, of Dayton was shot and killed while seated in his car. Two other people were wounded Saturday, one critically, during the attempted robbery of a convenience store.

The four were riding in a stolen car when they were arrested early Saturday, and the car's owner, Joe Wilkenson, was found shot to death in his home, police said.

The last two victims, 16-year-old Wendy Cottrill and an 18-year-old man whose name was not released, were found Sunday in a gravel dump on the city's west side. Police Chief James Newby said they probably were shot hours before the four were arrested.

Police would not release details of the fourth wounding.

Newby said police believe that the four knew the last two victims and shot them because ''they knew too much.'' He did not elaborate.

Police have said they do not believe the four knew the other victims. They did not say how they determined the shootings were related.