CALGARY -- Police say they have arrested a pastor who is also the father of a three-month-old baby boy who died in 2015.

Daniel Nel, 31, has been charged with second-degree murder.

His only child, Cyrus, was found in need of medical attention in August 2015 at the family's Calgary home after a 911 call. Paramedics took the boy to hospital but he died a day later.

Investigators had already said there was no plausible explanation for the injuries that led to Cyrus's death, but on Friday they wouldn't say how the boy died.

"This has been deemed a homicide and Cyrus died as a result of the injuries that were inflicted on him, but the specifics of that, we'll wait for court," said Insp. Don Coleman.

Last month, police asked anyone who knew anything about the boy's death to come forward and added they believed the injuries were inflicted inside the home.

Coleman said at the time that Cyrus's parents had participated to some degree with the investigation, but there was no "no plausible explanation that's been offered as to the injuries that led to Cyrus's death."

The public plea didn't coax anyone forward with new information that prompted the arrest, Coleman said.

"Nothing's really changed. It takes time to put the information together," he said. "There was no one thing that tipped the scale to charges."

There was a lengthy investigation involving consultation with a number of pediatric specialists.

"The people involved in that from a forensic pathology standpoint are incredibly busy and it just takes time," Coleman said. "Rushing through them doesn't do anything for the integrity of the investigation. Diligence and thoroughness takes time."

Nel is an associate pastor at a Calgary church and was put on administrative leave last month "until matters are further clarified."

"As a church community, we continue to pray for all who are involved," the Rockyview Alliance Church said in a statement at the time.

Nel is in custody and is scheduled to appear in court May 24.