Mark Vijay Chahal was 30 years old at the time of the killings in April 1996. Public records and contemporaneous news reports describe him as the estranged husband of Rajwar (Rajwar Kaur) Gakhal, who had divorced him in January 1995. Neighbourhood and police accounts that surfaced after the massacre indicated a history of domestic conflict: Rajwar and other family members had reportedly complained to police about incidents of spousal abuse prior to the shooting. Although Chahal did not have a criminal record that prosecutors relied on in the immediate aftermath, family members and acquaintances later painted a picture of a marriage riven by control, jealousy and repeated threats toward Rajwar and her relatives. Police statements at the time noted that Chahal had made explicit threats against his estranged wife’s family, reportedly saying none of the daughters in the family would ever marry. News coverage also reported that all firearms used in the massacre were registered to Chahal, and investigators later found evidence of deliberate planning, including a vehicle exchange prior to the attack that suggested he had prepared an escape.

On the morning of April 5, 1996, relatives of the Gakhal and Saran families were gathered at a Vernon home for wedding preparations. At about 10:30 a.m., Mark Vijay Chahal arrived at the home armed with two handguns — a .40‑calibre Smith & Wesson semi‑automatic pistol and a .38‑calibre revolver — and began shooting in the driveway, fatally wounding an older man (identified in reports as the ex‑wife’s father) who was washing his car. Chahal then approached the house and fired at windows before entering and moving methodically from room to room, firing at family members who were inside. The attack lasted an estimated three to four minutes. Two empty 10‑round magazines and numerous shell casings were later recovered at the scene. 

Immediate fatalities included several members of Rajwar Gakhal’s immediate family; other victims died later in hospital. Reporting identifies the victims as members of the Gakhal and Saran families, including the bride‑to‑be and several siblings and in‑laws. Two other family members—an elderly mother‑in‑law and a child—were reported injured but survived; two grandchildren in the house were unhurt. The exact roster of victims is documented in contemporary news lists and memorials produced by local media and community memorials. 

After leaving the home, Chahal drove to a nearby motel roughly 1.9–3 km away. There he wrote a note in which he apologized to family members and recorded telephone numbers; at about 11:00 a.m. he fatally shot himself in his motel room. Police later located a 12‑gauge pump‑action shotgun in his vehicle. Investigators concluded the massacre was premeditated: Chahal had exchanged his car for a rented van prior to the attack (interpreted as an attempt to conceal or facilitate escape) and had made prior threats to the family. Authorities treated motive as revenge — targeting his estranged wife and her relatives — although the deeper personal, cultural and social dynamics have been the subject of later commentary and analysis. 

The scale and brutality of the attack made it, at the time, the deadliest mass shooting in Canada since the 1989 École Polytechnique massacre. The massacre shocked the Vernon community and drew national media attention; vigils, memorials and survivor support efforts followed in the years after the killings. Local and national media coverage, survivor testimony, and later academic analyses have also examined how the incident was narrated in public discourse — including issues of domestic violence reporting, community memory, and the portrayal of South Asian victims in Canadian media.