BALTIMORE (AP) — A woman who authorities say confessed to suffocating her 1-year-old son in December has been arrested.

Baltimore police say 22-year-old Shakira Shaw was charged with murder on Monday.

Police say Shaw informed authorities last month that she had suffocated her son, Kaleb, in December.

Authorities say Kaleb was brought to a hospital last year and died there a short time later.

It’s not clear why he was initially taken to a hospital by firefighters.

An autopsy had determined he died from natural causes. It wasn’t clear if Shakira Shaw had an attorney who could comment.