Woman drowns her 2-year-old son in a fountain and then proceeds to shoot dead her nine-year-old daughter in car outside police station

A 36-year-old woman walked into a Missouri police station on Tuesday morning, May 28,  to tell officers that she had shot her daughter, 9, dead, leaving her in a car outside of the building, and that she drowned her son, 2, earlier that day.

Ashley Parmeley, 36, has been charged with the second-degree murder of her son, Isaac, while investigators prepare charges relating to the death of her daughter, Scarlett.

The car was seen outside of the station around 10:30am local time.

After Parmeley's confession, police began searching for her son. They found him dead in a fountain close to the Timber Creek Resort on the outskirts of St. Louis, 13 miles from the station.

Jefferson County Sheriff Dave Marshak said officers searched for a third child who has been found safe.

Officials have not released a motive for the horrific crime.

Sheriff Marshak noted that the children were accounted for and alive on Monday, May 27.

Then on the morning of May 28, Parmeley had changed her Facebook profile photo to a plain black image.

Another recent post featured a meme with an assault rifle and the words "Shall Not Be Infringed."

The sheriff described Parmeley as having "strong ties" to the local community and said that he didn't think she had ever been in trouble with the law before.

When she arrived at the police station, Parmeley's clothes were described as "wet" and "disheveled."

Photos published by the Associated Press showed police searching a silver Mazda SUV with Missouri license plates. Among the items retrieved from the vehicle was a bloody beach towel, the Post-Dispatch reported.

Officials are expected to provide an update on the case later.