HARTFORD, Mich. (WOOD) — A man has been charged for the murder of his girlfriend’s 18-month-old son last year.

Jacob Cody Tanner was charged with child abuse in the first degree and open murder for the death of Matthew Shayne Brown Jr., according to county jail records.

On April 23, 2021, Hartford Police Department and Van Buren County Sheriff’s Office were alerted that a toddler was brought to the Watervliet emergency room with severe trauma.

“There was suspicion immediately with it,” said the Van Buren County Sheriff, Dan Abbott.

The boy had to be airlifted to Kalamazoo. After undergoing surgeries and other unsuccessful life-saving measures, 18-month-old Matthew died the next day at Bronson Children’s Hospital, according to his obituary. Detectives and police ruled his death a homicide.

The sheriff’s detective bureau and Michigan State Police investigated Matthew’s death and narrowed the suspects down to the two last people who had seen the baby healthy — his mother and her live-in boyfriend, Tanner.

“They interviewed a lot of people. They had to narrow it down,” said Abbott. “Anytime you get a homicide investigation, you got to make sure you don’t make mistakes in an investigation. Because if you make one mistake, as you know in past history, somebody can get off on a homicide case by sloppy police work.”

Eventually, investigation narrowed the suspect down to Tanner, Abbott said.

An autopsy revealed that Matthew’s injuries, which were severe in his midsection, were “comparable to that of an injury of a severe car accident,” Abbott said. He added that he did not know what kind of abuse happened or what objects, if any, were used.

Abbott did not want to comment on details because of the trial but said, “I don’t think he (Tanner) was being truthful during the whole investigation,” adding that “a lot of stuff” did not check out.

Tanner is being held at the Van Buren County Jail without bond.

News 8’s David Horak contributed to this story.