JANESVILLE, Wis. -

Janesville police say the body of a woman found Monday morning is that of 21-year-old Britney Cross of Edgerton.

Janesville Police Chief David Moore said Cross died from a blunt impact head injury, and they're calling the case a homicide.

Clayton Courtney, 28, Cross' boyfriend, is the lone suspect in the case, according to Moore. He said they believe they know where she was killed, but were not willing to disclose it. He said they have confiscated items that could have been a weapon.

Moore said they don't know what Courtney's motive might have been.

Cross' body was found behind a former furniture store at 533 N. Main St. at 5:45 a.m. near where police say Cross and Courtney were together the day before, based on statements from witnesses.

Cross' body was discovered by officers as they were searching the area after a separate stabbing incident involving Courtney was believed to be in the area of the Rock River near the Memorial Street Bridge. Courtney had told others he was going to drink and do drugs with a female friend under the bridge.

The stabbing victim has been released from the hospital.

Courtney has declined to cooperate with the investigation, according to Moore.

Before the stabbing, Courtney said, "I've already killed three people tonight. We are all going to die," Moore said.

Police say if Courtney's claims are true, there could be more victims. On Tuesday, Moore said they have nothing to substantiate his comments and that they're encouraged that there have been no reports of missing people in the last day.

Police are asking the public for information for information about Cross, Courtney and their movements on May 1-5. They released a picture of Courtney's truck. They're interested in anyone who might have seen the truck during that stretch, and in particular on Sunday between 5 p.m. and 10 p.m.

Anyone with information on the case is asked to call Janesville police at 608-755-3100 or Janesville Area Crime Stoppers at 608-756-3636.

Courtney appeared in court Tuesday afternoon on charges related to the Sunday stabbing incident. His bail was set at $100,000, and he cannot have contact with the stabbing victim or his family.

The court also said Courtney cannot be assigned a public defender because he is currently employed. He will be back in court May 9.

Moore also said there are no developments in the case of missing woman Mary Coulthard.