MINNEAPOLIS (WCCO) — A Minneapolis father is accused of murdering his infant daughter while they were home alone.

Minneapolis police said the 4-month-old girl was assaulted and later died from her injuries on Saturday. The crime happened in the 1900 block of Franklin Ave. SE in the Prospect Park neighborhood of Minneapolis.

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On Sunday, investigators were working to determine how exactly the crime happened.

Minneapolis police spokesperson, Officer Corey Schmidt, said detectives were interviewing neighbors and the suspect’s family members.

“We are not actively looking for any other suspects in this case,” Schmidt said.

The 4-month-old girl’s father, Cory Morris, had been taken away from the home earlier in the evening Saturday. Morris is a 21-year-old who had only a few traffic tickets on his public record.

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Neighbors who had watched from behind their windows the night before were learning more about what police believe happened on Sunday.

One neighbor who told her story to detectives described her devastation to WCCO. She had watched first responders carry the girl from the home, and said she thought it was a doll at first.

Police believe father and daughter were alone at home when the child was assaulted. Police said it was unclear who called 911 for help around 5 p.m. on Saturday, but it was too late for the child.

“In a perfect world there would be no crime,” Schmidt said. “We are going to treat this like every case and we are going to do a thorough investigation.”

Schmidt said the facts will be presented to the county attorney’s office for any possible charges.

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WCCO spoke with members of the Morris family on Sunday, who only wanted to share that they are heartbroken over what has happened.