A man serving time for killing his infant son and trekking around the country with the child's body pleaded not guilty Friday to doing the same thing to his baby daughter.

Prosecutors contend that Jason Hann stuffed 2-month-old Montana Hann's corpse into a trash bag in 2001 then kept it in trailers and motorhomes for nine months as he and his girlfriend moved from state to state doing odd jobs.

The body was finally discovered in an Arkansas storage facility.

Hann, 34, pleaded not guilty in Indio Superior Court to murder and assaulting a child causing great bodily injury after being extradited from Kentucky, where he was serving time for killing his 6-week-old son 10 years ago.

Authorities said Hann had trekked around with the boy's body for 18 months.

Prosecutors in Riverside County were unsure if they would pursue the death penalty, district attorney's spokesman Michael Jeandron said.

It was unclear why it took so many years to bring charges against Hann in California involving the death of his daughter.

His attorney, Greg Johnson, said he had only been appointed by the court a day earlier and could not immediately comment.

Hann and the children's mother, Krissy Lynn Werntz, 29, were indicted by a Riverside County grand jury in September. Werntz previously pleaded not guilty.

The parents "should have been protecting them and nourishing them. It's a very sad case," Jeandron said.

A declaration in support of an arrest warrant said Hann told a Maine detective that he lost his temper and hit the girl in the head on Feb. 10, 2001, while the couple was living at a trailer park in Desert Hot Springs east of Los Angeles.

"Jason decided to keep Montana in a trash bag so they could keep her with them," according to the court declaration.

The couple eventually arrived in Arkansas and left the body in another trailer at a storage facility with the intent to return, the declaration said, citing Werntz.

The couple missed rental payments, however, and the managers sold their property. In February 2002, a man who bought the trailer found the girl's decomposed body wrapped in plastic bags, authorities said.

The couple was arrested two months later in Maine.

Hann told a Maine detective he was to blame for the death of his infant son Jason at a Shelburne, Vt., campground in 1999, the court declaration said.

"They kept the baby's remains inside a bowling ball bag and traveled the country with him for the next 18 months" before leaving it in a storage container in Lake Havasu, Ariz., when their daughter was born, according to the declaration.

In 2006, Hann pleaded guilty to second-degree murder in Vermont and was sentenced to serve 27 to 30 years at a prison in Kentucky.