PORTLAND – A couple wanted in Arkansas for allegedly killing their 5-month-old daughter was in custody Tuesday as authorities investigated whether they were responsible for the death of an infant son.

Police arrested Jason Hann, 27, and Krissy Werntz, 22, at a motel near the Maine Turnpike on Monday night. Their 1-month-old son, Jason, was placed in the care of the Maine Department of Human Services.

The pair face murder charges in Arkansas, where the body of their daughter, Montanna, was discovered in a plastic container in a camper trailer Feb. 18.

Werntz has given birth to at least three children, two of whom Hann beat to death while they were infants, said Police Chief Michael Chitwood. Authorities were trying to determine whether the couple, who followed a nomadic lifestyle for several years, had any other children.

“Based on what we’ve found out about these incidents, that baby was doomed to die,” Chitwood said. “I’m glad they’re off the street, and hopefully nothing has happened to this baby who’s now with DHS.”

Investigators believe Hann fatally beat his daughter in Wynne, Ark., where the camper was abandoned at a storage facility in October.

The camper was sold at auction, because storage fees went unpaid, before the unsuspecting buyer found Montanna’s body while cleaning the camper in Benton, Ark., Arkansas State Police said.

Chitwood said his department discovered the couple had another child named Jason who was beaten to death by Hann on July 4, 1999, in Burlington, Vt. The child, born in Youngstown, Ohio, was 5 weeks old, he said.

They then carried the baby in a Tupperware-like container for 18 months, Chitwood said, before abandoning that camper in Lake Havasu, Ariz. Next, Hann and Werntz went to California before returning Arizona, where Montanna was born.

In Arizona, detectives working Tuesday on information obtained from authorities in Arkansas found the body of a child in a plastic container in a camper in a commercial storage facility outside Lake Havasu City, Mohave County Sheriff Tom Sheahan said.

Police there were not saying the body is linked to the body found in Arkansas or to the couple held in Maine, but they say they are examining the similarities between the cases.

The second son named Jason was born in Fairmont, W.Va.

Arkansas authorities said the pair lived a “gypsy-style life, going from campground to campground across the United States.”