Maryland therapist drowns her 3-month-old baby in bathtub after waking up with plan to ‘end everything,’ cops say

The mother said she planned to leap out of a second-story window but changed her mind

A Maryland mother who drowned her 3-month-old daughter in a bathtub at her home has been charged with first-degree murder, according to court documents.

Mackenzie R Colgan, 37, called 911 on Sunday from her home in Chevy Chase, Maryland, to report that she had drowned her infant daughter in the bathtub, Montgomery County Police Department said.

First responders rushed to the house to try to save the girl, but were too late. She was later pronounced dead at the hospital.

Law & Crime reviewed a probable cause affidavit that provided a timeline of the alleged events on Sunday.

Around 11:40 am, Colgan allegedly took the child, who has not been named, from other family members, telling them she planned to bathe her upstairs.

Twenty minutes later, Colgan reportedly returned to the first floor and told the girl's father that the child had died in the bathtub. The father told Colgan to call 911 and ran upstairs to try to give the child CPR.

A police officer in Chevy Chase, Maryland exits the house where 37-year-old Mackenzie Colgan allegedly drowned her 3-month old daughter in a bathtub on December 8, 2024 (screengrab/ NBC 4 Washington)

After the first responder call to the house, police took Colgan in for an interview. During their talk, Colgan, a licensed clinical counselor, allegedly told detectives that when she woke up in the morning, she did so with a plan to "end everything."

She had allegedly determined she would kill both her children and her husband.

“She then said that she turned the baby to face away from her and held the victim’s head under the water until she knew the victim was dead,” cops wrote, according to Law & Crime.

She claimed she was going to jump out of the window of her home but changed her mind once she reached the ledge. That's when she told her husband about what she'd done to their child.

Colgan has been charged with first-degree murder and is now being held in Montgomery County Jail. A mental health evaluation has been ordered before her first court appearance.

Montgomery County District Attorney Lauren DeMarco, speaking to NBC 4, said the situation was “extremely sad.”

Colgan’s attorney confirmed to NBC 4 that the therapist had no prior convictions.