A man has been charged in connection with the death of four-year-old Rayna Gagne at her home in Cambridge.

Waterloo Regional police say Robert William Boettger, 28, has been charged with aggravated assault and was remanded in custody.

Boettger was the live-in partner of Gagne's mother, Jenn Taylor. Taylor is grief-stricken and says her daughter was an amazing little girl.

"She was perfect, she was very perfect, she would light up a room. She was always smiling and laughing and she was just, she was a very, very amazing little girl and I don't know what I'm going to do now."

Taylor returned from work on Thursday to find police cars at her home and paramedics working on her daughter.

Emergency services were reportedly called to the townhouse complex on Queen Street West for an unconscious child. They found the girl with life-threatening head injuries.

Gagne was transported to Cambridge Memorial Hospital and then transferred to Hamilton. She died in hospital on Saturday due to her injuries.

Police say a post mortem examination found head trauma was a contributing factor in her death, though further testing has been ordered.

Boettger made a court appearance via video on Monday. The investigation is ongoing and further charges are expected within the next few days.

Anyone with information is asked to contact police at 519-650-8500 Ext. 8669 or Crime Stoppers at 1-800-222-8477.

Neigbours react to devastating news

At the townhouse complex where Gagne lived people are saddened, sickened and angry at what has happened.

Neighbour Sharon Cromwell says "She was a great kid and very quiet. She never acted up and she called him ‘Daddy.'"

Shane Kongdara also lives nearby, he remembers a happy little girl playing with her friends in the yard.

"If I could give her my life I would," he says. "That girl was only a young four-year-old kid that didn't get to live her full life."

Gagne's organs were donated by her mother and Taylor says "If anything good is going to come from this I'm glad that she saved four people."

Memorial plans are underway and are expected to take place next week. A trust fund has also been set up for the family at the Bank of Montreal.