INDIO, Calif. -

Closing arguments are scheduled for Monday in the trial of Jason Michael Hann, who is accused with girlfriend Krissy Werntz in the death of their months-old child in a trailer outside Desert Hot Springs. Hann could face the death penalty if convicted. Werntz will be tried separately.

Hann has already been convicted of killing his infant son in Vermont. In both cases, the children's bodies were found decomposing inside of storage units.

The Riverside County District Attorney is seeking the death penalty against Jason Michael Hann, 38. He is accused of killing his two month old daughter, Montana, in a Desert Hot Springs RV park in 2001, then traveling around the country with the baby's remains for several months.

"The defendant wrapped this baby in trash bags and put her lifeless little body into a Tupperware-type container," Deputy District Attorney, Lisa DiMaria, said to the jury during opening statements.

Hann and the baby's mother, his girlfriend Krissy Lynn Werntz, left their daughter's remains in a storage unit in Arkansas. After the remains were found, Hann and Werntz were tracked down by law enforcement at a motel in Maine. 

The day after they were arrested, investigators found the remains of another of the couple's children in a storage unit in Arizona. Prosecutors say Hann admitted in a recorded interview with law enforcement to killing his six-week-old, first-born son, Jason, in 1999 and his two month old daughter Montana in Desert Hot Springs in 2001.

"He admitted to killing Jason," DiMaria said. "And he admitted to killing Montana."

Hann was sentenced to 27 to 30 years behind bars in Vermont, where he killed his first son. In opening statements, his defense attorney's did not dispute Hahn also killed his daughter.

"Jason Hann explodes. His rage explodes," Defense Attorney Brenda Miller said. "He hits Montana with a closed fist, and shortly thereafter, she dies."

The defense will argue Hann should not be convicted of murder in the first degree because of a bi-polar disorder and severe mental health issues.

"Because of his long long history of mental illness," Miller told the jury. "Whether he is guilty of murder 1. That is the issue."

If convicted of first degree murder in this case, Hann could face the death penalty.

"The death penalty is being sought in this case by District Attorney Paul Zellerbach due to the fact that the defendant in this case, Jason Hann, is convicted of a previous murder," said D.A.'s Office Spokesman, John Hall. "So with that conviction, we're allowed to seek the death penalty in this case in the death of Montana."

Werntz, 38, was not charged in the previous murder, but she will also stand trial for Montana's death early next year.