For the second time in less than two weeks, a Polk County dad has been accused of causing the death of his own baby.

In the newest case, Jacob David Hartley, 20, of Lakeland, was arrested by Polk County Sheriff's detectives Friday and charged with manslaughter of a child and aggravated child abuse in the death of his 3-week-old infant son.

Detectives said the infant’s mother, Amber Newton, found the infant unresponsive and bleeding from his nose and mouth just before 6 a.m. Friday. The infant, Colton Hartley, was transported to Bartow Memorial Hospital, where he was pronounced dead.

An autopsy determined Colton died of a head injury. The manner of death was ruled homicide.

Newton told detectives Hartley woke up at 10 a.m. Thursday and played Xbox until leaving for work at 2:30 p.m.

She said Hartley held Colton for a half-hour while playing the game and at one point shook him and cursed him for not going to sleep, allegedly saying, "[expletive] you, Colton, please got to [expletive] sleep."

According to detectives, Hartley admitted to shaking the infant approximately one week ago and again Thursday.

Last Wednesday, Christopher Ryon, of Winter Haven, was charged with aggravated manslaughter in the death of his 3-month-old daughter, Riley Ryon, a day earlier.

Detectives said the father admitted to hitting the baby in the head because she wouldn't stop crying when he wanted to take a nap.