"She could not handle her life."

That's why prosecutors say Maryland woman drugged her young son, put him in her car and then set the vehicle on fire.

Daniel Dana, 5, died June 16, 2015 after prosecutors say his mother, Narges Shafeirad, then 33, forced him to drink a bottle of medicine. She then locked his body inside a car that she set ablaze, officials said.

Shafeirad pleaded guilty Thursday morning to first-degree murder in exchange for a 50-year sentence. She showed no emotion in the courtroom as prosecutors accused her of killing her child. Information on the court proceedings was relayed to Shafeirad, who speaks Farsi, via an interpreter.

As News4 reported, on the day Daniel was killed, members of a Montgomery County fire and rescue crew initially thought they were responding to a car crash. A white 2003 Toyota Corolla was engulfed in flames about 3:30 a.m. at Sam Eig Highway (Route 370) and Fields Road, near the RIO Washingtonian Center shopping center.

Paramedics found Shafeirad face down outside the car, screaming. As first-responders began extinguishing the flames, they saw Daniel lying on the floorboard in the back seat. They tried to get into the car to save him, but the doors were locked, police said.

Investigators believe little Daniel died before the fire began.

Shafeirad was taken to a hospital with second- and third-degree burns on 40 percent of her body. She initially lied about what happened and then said she gave Daniel medicine because he had a fever, prosecutors said.

Investigators determined Shafeirad gave the child at least 4 ounces of the antihistamine diphenhydramine, which is the active ingredient in Benadryl. That's more than two-and-a-half times the amount that would kill an adult, prosecutors said Thursday.

Prosecutors believe Daniel fought for his life. He was found with cuts and bruises on his head and mouth.

The mother then doused the inside of the car with gasoline she kept in water bottles and set it aflame, prosecutors said.

Shafeirad and her husband, Hamid Azimi-Dana, were due in court for a hearing on the day she killed Daniel. Also, she had just lost her apartment.

"She could not handle her life and couldn't take care of the child, and did not want to give the child to the father and his new girlfriend," Montgomery County Assistant State's Attorney Marybeth Ayres said Thursday at a news conference.

Shafeirad had previously told the court that her husband had physically abused her for years, The Washington Post reported. Azimi-Dana said she had abused the child.

Daniel was bright, kind and inquisitive, the family's lawyers told the Post.

"He couldn't have been a nicer child," attorney David Gavin said.

Ayres said there is a lesson for any parent struggling through a custody battle: "Never, ever let your dispute get in the way of raising your child and putting that child's health and welfare first."

Shafeirad will be sentenced in December.