The mother charged in the death of her three-year-old son, Kaden Young, allegedly had both drugs and alcohol in her system when their minivan was swept into the Grand River last year, according to court documents.

The 35-year-old woman and her son were driving on 10th Line in Amaranth Township, near Orangeville, in the early morning hours of Feb. 21 when they drove past orange pylons and a road closure sign.

The minivan became struck and ended up in the river.

As she tried to free Kaden from his car seat, Ontario Provincial Police said the little boy and his mother were swept into the raging current. She was able to hold on to her son briefly, but soon lost her grip.

Emergency crews later rescued the mother along the banks of the river. The toddler’s body was found after a two-month search by police, family and volunteers. An autopsy later confirmed Kaden died from drowning.

Michelle Hanson was charged with impaired driving causing death, dangerous driving causing death, and criminal negligence causing death in October.

While the criminal case is ongoing, documents from a child custody decision between Hanson and Kaden’s father, Cam Young, has shed more light on the investigation

The documents indicate that Ontario Superior Court judge Erika Chozik reviewed information from the Dufferin Child and Family Services (DCAFS) as part of her decision. The information, contained in a letter, refers to toxicology tests OPP conducted on Hanson the night the van plunged into the river.

In her decision, Chozik made it clear that she never personally reviewed the toxicology tests herself.

According to the letter from DCAFS, OPP toxicology screens showed that Hanson allegedly tested positive for Percocet, OxyContin, cocaine and alcohol.

It says Hanson also denied being impaired at the time of Kaden’s death when questioned by DCAFS.

An affidavit submitted by Cam Young claims Hanson told him she was going to the store to buy cigarettes sometime between midnight and 12:30 a.m. that day. Kaden was still awake at the time, so Hanson reportedly suggested she take him with her for a car ride to help him fall asleep.

The judge ruled that, based on the affidavit, the father “either agreed or did not oppose this proposal.”

The documents show Hanson called Young about 20 minutes later, saying she was trapped in the raging river.

The allegations have not been proven in court.

Hanson is due to appear in court again on April 9 for a judicial pretrial.