AURORA, Colo. (KDVR) — FOX31 has learned more about what investigators will be looking for in the case involving a dentist from Aurora accused of poisoning his wife to death.

FOX31 also talked to patients of that dentist, Dr. James Craig. Those patients have lingering questions about their experience at his clinic.

For years, Craig had been practicing at his office in Aurora on East Hampden.

Craig was arrested Sunday for allegedly poisoning his wife to death.

Autopsy may be the key

One of the key elements in the case is what was in Angela Craig’s system when she died, according to FOX31 Legal Analyst George Brauchler.

“We’ve got to get the toxicology back. We have to know what the autopsy reveals and they [prosecutors] need to be interviewing all the other people outside of the victim’s immediate family, as well as the paramour,” Brauchler said.          

In a police affidavit, investigators alleged Craig was having an affair, had bought poisons online and had gone bankrupt.

Former patients surprised, concerned

A former patient said she saw the dentist’s family in his office several times. She’s having a hard time with what’s happened.

“It was weird. I’m still completely shocked. I cannot believe it, it blows my mind,” former patient Rita Gerdemann said.

Gerdemann also has questions about the amount of and quality of work done during her visits.

Dustin Pickering was also a patient and said he was satisfied with what Craig did for him. But he now has concerns about his dental care and said no one is answering his calls.

“Now, I don’t know what’s going on and this [dental work] is something that needs to be done or otherwise I’m going to have an implant that’s going to fail. I’m a little confused and stressed out,” Pickering said.

The office where Craig worked was closed when FOX31 went by on Tuesday. FOX31 attempted to reach someone by phone at the location but did not hear back.

Angela’s family has not responded to requests for comment.