A Michigan man is accused of killing his wife by adding heroin to her cereal

A Michigan man is currently in prison for murder for allegedly killing his wife by doping her grain with heroin.

Jason Harris, 44, of Davison, was arrested on Tuesday and charged with the death of his wife five years ago.

When Christina Ann-Thompson Harris, 36, died in September 2014 after being found insensitive to her home, it was deemed that an accidental overdose had been reported, said Genesee County Attorney, David Leyton, at a press conference.

The day she was found, a neighbor told the police that Harris had called to ask him to check his wife.

When the neighbor found Christina Harris in bed and was unable to wake her, she called another neighbor, a nurse. The nurse realized that the woman had died and called 911.

By the time the police arrived, Jason Harris was there. He told police that his wife had a cold and that at the time of her departure for work, she was coughing and sleeping in restless sleep, said Leyton at a press conference Tuesday.

A medical examiner said his death was due to accidental toxicity of heroin, a decision that shocked his family and friends.

Many people who knew Christina Harris, a mother of two, including a baby, said "she would never use drugs, let alone heroin," said Leyton. "By all accounts, Christina Harris was an incredibly loving mother."

Prosecutors now believe that Jason Harris "murdered his wife," said the prosecutor. "We think that he put heroin in his cereal and milk the night of his death."

Shortly after his death, the police began hearing troubling new details about Jason Harris's relationship with his wife. In October 2014, two of his siblings went to the police to say that their brother may have had an affair prior to his wife's death and that they had heard about his willingness to "get rid of Christina," said Leyton.

Christina Harris' mother told the police that she had been with her daughter the day before she died and that she was not sick. She described her daughter's marriage to Jason Harris as "difficult".

A neighbor said that Jason Harris had told them that the day before his wife's death, he had given her cereals and milk. She dropped the bowl and fainted while eating, said the prosecutor.

His colleagues told the detectives that before the death of his wife, Jason Harris had said he had put five Xanax tablets in his wife's water, but that after tasting it, she would not drink anymore. He had also hired a hitman to kill his wife, but the man was arrested for a crime unrelated to him while Christina Harris was under surveillance, Leyton said. Jason Harris then asked a colleague if he wanted to kill his wife.

Jason Harris did not want to divorce his wife because he did not want to pay child support and he feared that his children would be taken away from him, the prosecutor said.

The investigation also revealed that Jason Harris had contacted "many women" before and after the death of his wife, Leyton said.

After a multi-year investigation, a medical examiner last week changed the cause of Christina Harris' death into a homicide.

Jason Harris has been charged with premeditated murder, murder and delivery of a controlled substance.

His lawyer told NBC News in a statement that he had pleaded not guilty to the charges against him "and hopes to prove his innocence in the unfortunate death of his wife".

"Mr. Harris has been totally cooperative throughout this investigation that has lasted nearly five years and was disappointed to learn that the initial findings of an accidental overdose have now been ruled out," said Dr. Lawyer Nicholas Robinson.