A Brooklyn Park man has been charged with murder after his 2-month-old son was found dead with a skull fracture, bleeding on the brain and other broken bones, according to charges.

Derrick T. Johnson, 19, was charged Monday in Hennepin County District Court with one count of second-degree murder without intent.

According to the complaint:

Police were called to Johnson's home on Sept. 3 about an unconscious baby. They found Johnson in a third-floor stairwell carrying the baby.

Johnson told authorities the baby fell off the bed and hit the side of his head while he was in the bathroom. He said he was home alone with the boy at the time.

The baby was not breathing and did not have a pulse when authorities arrived. Police also saw several holes in a wall of the home.

Officers performed CPR before firefighters arrived and transported the baby to the hospital.

An emergency room doctor told police the baby had likely died 30 minutes to two hours before he arrived at the hospital, the charges said.

Johnson had told police he called 911 about 25 minutes after he saw the baby on the floor.

Outside of the medical examiner's office, according to the complaint, Johnson told a detective that the baby was squirmy, had no prior injuries and had fallen off the bed and perhaps hit an oscillating fan.

The detective overheard Johnson tell relatives that he dropped the baby.

A doctor who reviewed the medical examiner's autopsy found that the baby had a skull fracture, bleeding on the surface of the brain and bruising near the eye and temple consistent with a significant injury, the charges said.

The baby also had a broken right clavicle, a healing broken left clavicle and rib fractures close to the spine.

The doctor determined that the injuries were consistent with abuse and not a fall, although a final autopsy report is pending.

Johnson is in custody at the Hennepin County jail.

Chao Xiong • 612-270-4708 Twitter: @ChaoStrib