It was reported that the father drove to Oregon on Friday to pick up his son.I read the same. My own speculation is that, out of an abundance of caution, the boy is in care of his paternal grandparents / relatives / etc such that LE can assess any claims of DV against his father in addition to whatever caused his mother to leave Canada with him.
This leaves the child (presumably) in the care of relatives he knows / feels safe and comfortable with, while allowing LE to untangle any kind of custody dispute.
Quite likely he is released to the custody of his father soon, but this is a cautious intermediate step IMO
Although Dawn Walker has filed complaints of domestic violence with police against a former partner, and police have investigated those complaints, there have been no charges against the father. Those complaints are closed.
There would be no reason to re-investigate the father (if he is indeed the subject of the complaint) after Dawn abducted his child and transported that child to a foreign country. The father is one of the two legal guardians of the child.
"U.S. agency representatives in consultation with the SPS are currently working out the details of returning Vincent Jansen to a legal guardian."
Update - Missing Persons Located
The Saskatoon Police Service in conjunction with the United States Department of Homeland Security have located missing persons Dawn Walker and her son Vincent Jansen. The two were found in Oregon City, Oregon at approximately 11:30hrs (CST). Both are reported to be safe and well. Agency...
saskatoonpolice.ca
There doesn't appear to be anything to untangle regarding custody. The father clearly has shared custody rights, which is why Dawn could not legally move to another city with the child. She could leave anytime, the child had to remain in Saskatoon.
What should happen, to protect the child from further abduction and potential psychological harm, is that the father is given sole custody and the mother is given supervised visitation at some point in the future.