The stepfather accused of fatally beating a 3-year-old inside a Brooklyn homeless shelter will be charged with second-degree murder, according to Brooklyn District Attorney Ken Thompson.

The upgraded charge comes after the medical examiner determined that the death of Jeida Torres was a homicide. Her stepfather, Kelsey Smith, had been originally charged with assault and acting in a manner injurious to a child under 17 years old.

Neighbors at 38 Cooper St. called police after hearing screams at around 4 p.m. Saturday. Officers arrived to find the toddler unconscious and unresponsive. She had bruising on her body, police say.

The child was rushed to Wyckoff Heights Medical Center in cardiac arrest, and was pronounced dead.

The girl's 5-year-old brother was also found with bruising on his body. He is currently listed in stable condition at the hospital.

Authorities say Smith was caring for the two children while their 24-year-old mother was at work.

Police say the victim's brother gave a detailed account of the incident, saying Smith banged his sister's head against a bed frame and then choked her.

Police say that Smith is currently at Bellevue Hospital after they say he tried to slit his wrists. They say the suspect was found at a relative's home in Queens.

Authorities say he has had 15 prior arrests, including one for assault.

The victim's brother told investigators that Smith beat his sister because she soiled her diaper.