William Francis Melchert-Dinkel, 46, may be charged in the death of 18-year-old Carleton University student Nadia Kajouji "within the next couple of weeks," St. Paul, Minn., police spokesman Peter Panos said, The Ottawa Citizen reported Friday.
For at least 14 years before allegedly preying on Kajouji, who was suffering from depression, Melchert-Dinkel allegedly developed a disciplinary record with the Minnesota Board of Nursing, police said.
Allegations include failing to tell a doctor in 1994 about a patient's rapidly deteriorating condition, leading to the patient's death, and abusing nursing home residents, for which he had his license restricted in 1998, the Citizen said.
The board cited him for repeated clinical shortcomings, including "poor critical thinking skills," "clinical weakness" and "unsafe" behavior, the newspaper said.
Melchert-Dinkel had his nursing license suspended 22 days ago for undisclosed reasons, the newspaper said.
Police said they recovered information from Melchert-Dinkel's home computer after receiving a tip he was involved in encouraging, advising and assisting people to commit suicide through the Internet.
Kajouji had been conversing with a man online just before she disappeared March 9, 2008, police said.
She was found dead in Ottawa's Rideau River of an apparent suicide April 20, 2008, after more than five weeks of searching.