Police have charged a father with first-degree murder after his 11-year-old daughter, who has been described as a “sparkle” and high-achiever by her school, was found dead at a Brampton home.

Riya Rajkumar was supposed to be celebrating her birthday with her father, Roopesh Rajkumar, on Thursday evening, but when she wasn’t returned to her mother on time, concerns about her wellbeing grew.

Her mother contacted police at around 7 p.m., authorities said, after Roopesh Rajkumar, 41, allegedly made alarming comments to her about plans to harm both himself and his child.

“She (the mother) came in already fully concerned saying, ‘This is what he was saying to me, I am concerned for the wellbeing of my daughter and I need some help,” Peel regional police Const. Danny Marttini said.

Riya became the subject of an Amber Alert at around 11:30 p.m.

An hour later, the alert was cancelled, after police found the young girl dead in the basement of a Brampton duplex where her father lived.

Roopesh Rajkumar was arrested about 130 kilometres away, near Orillia, Ont., by Ontario Provincial Police in what’s been described as a “high-risk takedown.” He was transferred into the custody of Peel Regional Police on Friday morning and formally charged with first-degree murder in the afternoon.

Police said Rajkumar was located as “a direct result” of someone receiving the Amber Alert.

Police said the suspect’s health delayed that process.

“When we did take custody of the individual earlier this morning, our officers at that time did notice that there was a medical concern. They were concerned about his wellbeing,” Const. Danny Marttini said at an afternoon news conference.

Rajkumar was taken to a local hospital for treatment and eventually transferred to a Toronto-area trauma centre for additional care. He was charged over the phone and remains in the hospital.

It’s not known what Rajkumar is being treated for in hospital or the severity of his condition.

“All I know is that there was a medical issue,” she said. “We will standby until he is medically cleared.”

Riya remembered by her classmates and community

Riya’s peers and teachers arrived at Meadowvale Village Public School in Mississauga on Friday morning to a memorial table assembled in the Grade 5 student’s honour.

Principal Stacey Service said Riya’s death is being felt “deeply by everyone at the school.”

Grief counsellors have been made available at the school for those struggling with the news of her death. Teachers were also provided with a “script” to deliver to students about the situation.

Students and staff have been encouraged to visit the memorial in the school library and leave messages of condolence or memories of the young girl.

“What I understand from the staff in the building is that Riya was a sparkle,” Carla Pereira, the communications director for Peel District School Board said.

“She was a firecracker. She was very well liked. She achieved very well, she was successful in school. She had lots of friends and was very popular.”

Condolences for the young girl have poured in since the news of her passing. Outside the Brampton home where her body was found, mourners placed flower bouquets against a tree near the property.

“It’s just an innocent child,” said one woman. “I have children of my own. I could never imagine.”

Ontario Premier Doug Ford was among those who expressed their sympathies on Twitter.

“As a father of four daughters, I’m truly at a loss for words. 11 years old. My heart is broken for Riya’s mom who is living every parent’s worst nightmare,” Ford said. “Karla and I are keeping Riya’s family and community at Meadowvale Village PS in our prayers.”

Prime Minister Justin Trudeau joined the mourners as well, offering credit to the Amber Alert system.

"Amber Alerts like the one so many of us received last night are critically important to helping police when a child's life is on the line," he wrote. "My deepest condolences to everyone mourning young Riya today."

Timeline of the investigation

From the moment they received the complaint from Riya’s mother, Marttini said, police started to feed detailed information about the girl, her father and their vehicle to officers on patrol.

Some officers were tasked with ground searches, including checking on places the pair frequented.

Marttini said officers did a “door knock” at the Brampton home where Riya was later found, but at that time, did not have sufficient information to force entry.

“If nobody answers, that’s sort of as far as we go. The vehicle wasn’t there. We didn’t have anything else to go on,” she said. “As the investigation unfolded, they did receive information that they did believe she was in the residence. As soon as they had that information, they proceeded with that.”

“If they felt the circumstances were there. They would have proceeded.”

Peel police then requested OPP issue an Amber Alert. The alert was issued at around 11:30 p.m. but Riya was found dead approximately 30 minutes prior.

Marttini wouldn’t speculate on the outcome had the alert been issued earlier.

“There is a process, like anything. There’s a procedure for everything and it must be followed,” she said.

“The reality is that it’s a very difficult situation. The investigating officers did everything they felt they could do during the entire process. It is a very unfortunate outcome and everyone has to deal with that.”

Since the discovery overnight, forensic teams have descended on the Brampton home near Queen Street and Highway 410, where they continue to comb for evidence.

The home is completely taped off by police and several cruisers remain parked nearby.

Marttini described it as an “active scene.”

“They will be taking photographs, they will be collecting pieces of evidence… Everything we need to make sure we have all the information about what occurred inside the residence,” she said.

Riya did not live with her father on a full-time basis, according to police. She was reportedly dropped off at a gas station in Mississauga at around 3 p.m. on Thursday, where her father picked her up to take her out for her birthday.

She would not say how the girl died, noting that an autopsy will be performed.

“They were celebrating a joint birthday,” Marttini said of Riya and her mother.

“It’s very heart wrenching. We have to remember, this is a family, and she’s now moving on without her daughter. It’s very traumatic.

Nancy Ali, the aunt of Roopesh Rajkumar, told reporters Friday afternoon that their family is “speechless.”

“I know he is a very good guy, hardworking,” she said. “I saw him just the other day when he said he was coming to pick up his daughter for her birthday.”

Ali said that the family was at a wedding in Florida last month and everyone seemed happy.

“So tragic,” she said. “We were all shocked, from here to New York to Guyana. We were all shocked.”

Reaction to Amber Alert activation

The activation of the Amber Alert System for Riya Rajkumar was heard and seen on mobile devices across Ontario.

Peel police said the fact someone spotted Roopesh Rajkumar after reading the alert proves that “the system works.”

Despite this, the police service reported receiving numerous 911 calls from people complaining about the alert and the time it was issued. Police called the reaction "unfortunate" and urged people to consider the gravity of the situation they were being notified of.