A Charlottetown high school will host a big game of catch Monday afternoon to pay tribute to two of its former baseball stars, who were killed late last week in a murder-suicide on a stretch of highway in Alberta.

The game is scheduled for 3:20 p.m. at Colonel Gray High School, where Tanner Craswell, 22, and Mitchell MacLean, 20, were once promising young athletes.

Colonel Gray principal Kevin Whitrow said a game of catch is a fitting tribute for Craswell and MacLean, who were best friends and played together for the Lethbridge Bulls in a collegiate summer baseball league.

"I think there is a fair amount of interest in the community to say this is something that would be an honour to the kids and an honour to their families, to have people come together and do something that the guys loved to do," Whitrow told CTV Atlantic.

The young men were killed early Thursday morning alongside their friend Tabitha Stepple, 21, after Stepple's ex-boyfriend ran their car off of Highway 2 near Lethbridge and began shooting.

Police say the shooter, 21-year-old Derek Jensen, had been looking for Stepple after a confrontation at a pub on Wednesday night.

The driver of the car, Shayna Conway, 21, was shot several times, but is expected to survive. At the end of the rampage, Jensen fatally shot himself.

Friends said Stepple and Conway were driving the two men to Calgary, so they could catch a flight home to P.E.I. for Christmas.

RCMP said Saturday that Jensen followed the foursome after spotting their car at a 7-Eleven convenience store in Claresholm. Jensen had three loaded weapons with him: a handgun, a shotgun and a rifle. All were registered.

RCMP Sgt. Patrick Webb said investigators are examining "a domestic violence, jilted-boyfriend motive" in the slayings.

"We can surmise there was definitely a certain amount of planning in this," Webb told a news conference in nearby High River. "No one drives around for the most part with three loaded weapons. Exactly how they were to be utilized or what his intentions were, we may never know."

Witnesses told CTV News that Jensen went "berserk" when he saw Stepple, Conway, Craswell and MacLean celebrating Craswell's birthday at a Lethbridge pub. Stepple's friend Caitlin McFarland said Jensen began yelling and pushed Stepple out of her chair.

Jensen and Stepple had broken up a few months earlier and were in the process of moving out of their shared home.

The coach of the Lethbridge Bulls said he had planned to drive his two players to the airport the day before, but they had decided to stay an extra day to celebrate Craswell's birthday.

"Those boys had nothing to do with (Jensen)," said Kevin Kwane, who was also the players' landlord. "They were in the wrong place at the wrong time."

While playing for the Bulls, MacLean was named rookie of the year and Craswell was an all-star shortstop.

"The whole P.E.I. community is saddened," said Baseball P.E.I. president Don Leclair, who had watched the young men's short careers. "A number of my children went to school in western Canada and I know the excitement you felt waiting at the airport and now these people are waiting for their caskets to come."

With a report from CTV Atlantic's David Bell