OMAHA, Neb. -- Police in North Platte, Neb., said Monday the evidence in last week's double slaying overwhelmingly points to two teenagers arrested at gunpoint in Wyoming Friday after a chase.

The teens -- 15-year-old Alisha Ochoa and 18-year-old Michael Grandon -- will likely be back in Nebraska by the end of the week to face charges because they agreed Monday not to fight extradition.

Police believe Grandon and Ochoa killed Ochoa's mother, 39-year-old Lori Solie, and her half sister, 5-year-old Tiara Solie, in a North Platte apartment Thursday night. Both victims were stabbed several times.

"We have developed overwhelming evidence," North Platte Police Chief Martin Gutschenritter said.

The two teenagers fled North Platte in Solie's black 2006 Ford Mustang, and arrest warrants for car theft were issued last week.

Lincoln County (Neb.) Attorney Jeff Meyer said he's still reviewing the evidence and hasn't decided what additional charges to file besides car theft. But Meyer said he expects to charge the two teenagers as adults when he does file charges related to the slayings.

Two North Platte investigators interviewed Ochoa and Grandon in Wyoming over the weekend, but Gutschenritter refused to discuss details of the case developing against the two teenagers.

Sweetwater County prosecutors charged Grandon Monday with felony possession of stolen property because he was driving when he and Ochoa ran a roadblock and tried to elude police during a 67-mile chase.

Any charges filed against Ochoa in Wyoming would be confidential because she is a juvenile, said Terry Rogers, a deputy Sweetwater County attorney.

In an affidavit filed in support of the charges, Wyoming State Trooper Jason Caudill said the Mustang was spotted traveling 125 mph Friday morning on Interstate 80 between Rawlins and Rock Springs.

Grandon managed to swerve around one police roadblock in Solie's stolen Mustang before crashing into Caudill's patrol car at a second one.

Ochoa and Grandon were arrested at gunpoint after the crash, and have been held in the Sweetwater County Detention Center since Friday.