Florida couple pose as Amazon delivery workers and kidnap a 7-month-old baby.

NEW: Florida couple drives 45 hours to Washington to pose as Amazon delivery workers and kidnap a 7-month-old baby.

Insanity.

Marlly Jarina Ardila-Urrego and husband Chun Ho Vincent Lai have been arrested for kidnapping, burglary, and assault.

The couple drove to Seattle where they pretended to be Amazon delivery drivers.

They then entered the mother's home, who is Ardila-Urrego's cousin, and beat her before taking the baby and cell phones.

According to the mother, the couple told her they purchased a bed frame that would be delivered at the house on Feb 20.

After her husband left for work, there was a knock at the door. When she looked through the peep hole she saw an Amazon delivery worker.

When she opened the door, she was punched in the face and zip tied. Her baby was then abducted.

The couple put the baby in an Amazon box and left.

Four hours later, police intercepted the couple on the I-90. The baby was uninjured.

At the moment, there is no known motive for the crime however police say there is *no* evidence "that mental illness or substance abuse contributed to this crime."

The couple has been charged with first-degree kidnapping, robbery & burglary, and second-degree assault of a child.

The child they allegedly assaulted was the woman's other kid, a two year old.