CTV News has learned the two teens charged with planning a major killing spree in Winnipeg have spent time in psychiatric institutions, and that they had no intention of being taken alive after the attack they allegedly planned.

Police have charged a 17-year-old boy and girl with four counts each of conspiracy to commit murder, along with other charges relating to the theft of four rifles and ammunition.

Investigators believe the pair began formulating a plan last October to go on a shooting rampage at the Lorette Collegiate, the Fort Richmond Collegiate, the University of Manitoba, and Church of the Rock.

One of the teens is former student at Lorette Collegiate, the other is a current student at Fort Richmond.

Pastor Mark Hughes from Church of the Rock says one of the accused was part of a youth group at his church.

There is no clear indication as to why the U of M was an alleged target, but sources say part of the alleged plot included waiting until a classroom was full, in order to inflict as much carnage as possible.

"Primarily their intentions were to harm a number of persons at random," Cons. Jacqueline Chaput said. "This included students, adults, church parishioners, and pretty much anyone that was going to get in their way as they attempted to allegedly carry out their plans."

"It is very disturbing to us," she said. "To my knowledge we have not encountered something this serious yet."

Police say the suspects had four stolen rifles in their possession, along with an undisclosed amount of ammunition.

CTV News has learned they had allegedly gone so far as to do test runs of the shootings, timing out how long it would take to speed away from their various targets.

Police became aware of the plans after raiding a Waverley Heights home Jan. 9. They were acting on a tip that there were guns inside.

That is where they found the four rifles, which had been stolen from one of the suspect's relatives last November.

After the raid, police arrested the male suspect and charged him with break-and-enter and various firearms offences.

He was released on a promise to appear.

As police continued to investigate the incident they uncovered the shooting spree plan.

Police arrested the girl Thursday and re-arrested the boy early Friday morning.

Police believe the two teens did not involve anyone else in their plans.

It is not clear when the suspects planned to carry out their attack.

With a report from CTV's Kelly Dehn