The brother of disabled 23-year-old single mother, who police say was killed in a targeted bomb attack, says he has no idea who would want to harm her.

"She's done nothing, nothing that would merit something like this," Trevour Shachtay told CTV News. "She didn't have any enemies. She didn't get any threats or anything like that."

Victoria Shachtay was killed last week after a mail bomb exploded at her townhouse complex in Innisfail, about 100 kilometres north of Calgary.

The crime has shaken the community and no one has been arrested. Shachtay says he's having a difficult time trying to make sense of his sister's death.

"I need to know, I need to know what happened," he said.

Police said the exploding package was delivered by hand, not through the mail. Investigators say they do not have a suspect yet, but have a number of leads and some information that only the killer would know.

Shachtay describes his sister as a devoted mother to her seven-year-old daughter and an active member of her church.

Victoria Shachtay had been confined to a wheelchair since she was 16, after her spine was injured in a car accident.

Trevour Shactay had a message for his sister's killer.

"I don't know if you're hiding or if you're thinking this is some kind of sick joke but this is killing everybody," he said.

With a report from CTV's Alberta Bureau Chief Janet Dirks