The federal investigator looking into the death of Ashley Smith says he wants to know more about why charges were dropped against four employees at the Grand Valley Institution for Women in Ontario earlier this week.

Former guards Karen Eves, Blaine Phibbs, Valentino Burnett and supervisor Travis McDonald had been charged with criminal negligence causing death in the Oct. 19, 2007, suicide of the 19-year-old Moncton woman.

In a Kitchener, Ont., courtroom on Monday, the Crown said new medical opinions found the four prison employees could not have reached Smith in time to save her life.

The decision to drop the charges came two-thirds of the way through a three-week preliminary hearing to decide if there was enough evidence to send the matter to trial.

Howard Sapers, Canada's federal prison ombudsman, has done his own investigation for the federal government. While Sapers didn't attend the preliminary hearing he'd like to know more about what came out.

"We'll have to wait and see whether this means the end of all criminal investigations into Ashley Smith's death or whether this closes this chapter and opens another," Sapers said.

Sapers said he'd like to compare the Crown's evidence to what he discovered.

He said Corrections Canada has had his recommendations on how to prevent similar deaths for more than five months and he hasn't seen much action in that time.

"When I made those recommendations, they were presented with a certain urgency and I want to receive a full accounting from the service as to how much progress they've made," the federal prison ombudsman said.

Sapers said he was going to give Corrections Canada enough time to respond to his report before making it public. Now, given everything that's happened in this case, he's trying to decide whether he should wait any longer.

"To this point, I'm not satisfied that the response has been fulsome," Sapers said. "So I'm waiting for some additional movement on their part as well as some additional explanation on their part as to what they have done."

Along with four other employees, the four accused were suspended after Smith's death pending an internal investigation by Correctional Service Canada. Those charged were later fired, along with two managers.