PHOENIX – A man whose ex-girlfriend wanted him to take a paternity test is charged with her murder after allegedly admitting he killed her and set her body on fire.

Antwaun Ware is held on $1 million bond in the death of 21-year-old Jasmine Dunbar.

According to the police report in the case, at just before 10 p.m. on March 3, police found an infant girl alone in a car seat on the road in 49-degree temperatures. Along with the baby, police found one adult shoe, a diaper bag and a wallet with Dunbar's ID inside.

Get Breaking News Delivered to Your Inbox

Police contacted Dunbar's godmother who said Dunbar had a 7-month-old daughter and that earlier that evening she had said she was going to meet Ware to get him to take a paternity test. The paternity of the child "was in question," Phoenix police Sgt. Jonathan Howard said Thursday.

Another ex-boyfriend of Dunbar's and her godmother separately told police that they last saw Dunbar leaving her apartment with Ware and that she said she and Ware were going to do the paternity test, the document said.

According to the report, when officers first contacted Ware, he said that he'd picked Dunbar and her daughter up and dropped her back off after they got in an argument. But he later changed his story, and allegedly told officers that he punched Dunbar and left her in field.

Ware "admitted he had a physical altercation with Jasmine and punched her a number of times with his fist," police said in a probable cause statement.

He said he then dropped the baby girl off near his girlfriend's in a place he thought people would see her and take care of her, then returned to Dunbar, and set her body ablaze with gasoline.

He said he watched Dunbar's body as it burned, reports CBS affiliate KPHO.

Ware then allegedly told police that he went back to the area where he'd dropped off the infant, saw police, and went a back way to get to his girlfriend's house.

Police say that they used cell records to locate where Ware's phone had been and through that were able to find a partially burned body they believe is Dunbar's.

KPHO reports that Ware is charged with one count of first-degree murder, one count of kidnapping, one count of abandonment of a body and one count of child abuse.