"I just hope it is the right people, because they deserve to be caught," said Christianne Odehnal, who had known Osegueda for more than 15 years.
"But it's not a relief, because they took her life and we'll never get it back again."
Mexican media have reported that two men and three women have been arrested in connection with the robbery-related deaths of Osegueda, 39, and her 38-year-old boyfriend Alejandro Santamaria.
Three other suspects still remain at large, reports said.
Osegueda, who was completing her PhD at the University of British Columbia, was visiting the Mexican province of Oaxaca as part of her research. She and her boyfriend disappeared on Dec. 14.
Family members, fearful the pair had been abducted, raised the alarm and mounted a search to look for them.
Osegueda's ex-husband, Jacy Wright, discovered their charred bodies half buried on a beach near the resort town of Huatulco in early January. Police said Osegueda and Santamaria had both been stabbed in the neck and set ablaze.
Odehnal, who met Osegueda through a Vancouver gym, expressed some concern about the pressure the Mexican police were under to find suspects.
"You want to make sure that these are the right people, and [the police] aren't just saying this to make Mexico look good," said Odehnal. "You know, there was a lot of press. It even reached Brazil, where I'm from. So they were probably afraid to look bad in front of the rest of the world."
Wright addressed the news of the arrests in a Facebook posting Monday night.
"The man who did the deed is still at large but I have confidence he and the other two gang members still at large will be caught," the posting said.
"Their deeds cost me a great deal, on many levels, but I know I did what I could for her, I know I had to do it and I know I won't let them or anyone else break me."
Robbery appears to have been the motive behind the deaths, state prosecutor Manuel de Jesus Lopez told local media on Monday. Gang members allegedly made off with the couple's bank cards and cell phones as well as Osegueda's Chevrolet, he said.
This fits with what Odehnal knows about the case, which included a break-in at Osegueda's mother's house two days after Osegueda disappeared.
"They used a key that was on the keychain of the car," Odehnal said. "Luckily her mother wasn't there, because they actually went to the mother's home and they stole some electronics and things. If her mother had been there, she probably would have been another victim."
"It sounds like they were after material things," said Odehnal. "The car, the money."
It was the car that ultimately led to a break in the case, according to Lopez. Using the vehicle's global positioning system, police tracked it to the home of a local gang member's girlfriend.
By the time police made the connection, however, both the gang member and his girlfriend were already dead in what investigators described as a settling of accounts.
Monday's arrests centred on alleged members of the Las Zetas cartel, police said.
Lopez told reporters that police have already disbanded four local criminal groups dedicated to kidnappings. He also cited a recent increase in the number of killings in the coastal region.
Osegueda's death touched off a wave of widespread mourning earlier this year, along with a renewed call for Canadian tourists to steer clear of Mexico.
-- with files from Michelle McQuigge in Toronto
Note to readers: This is a corrected story. An earlier version said the couple was killed in January.Suggest a correction