Well, they probably were lumbermen. Some of them worked in the sawmill when they were living on Manitoulin Island before they went out west.
The story goes that the man was away working at one of the camps and someone told him his wife was cheating. He went home for his scheduled visit and never mentioned anything. When the time came to leave he pretended to leave, but stuck around. That night he went into the house and removed the baby and took (her?) next door to the neighbour and asked if they could watch her. (Probably said there had been a death in the family!) Then went back in the house and killed the wife and then her lover. Story a) has him shooting them, and story b) has him using an axe. Then he disappeared and was never seen again. It is stressed that he killed his wife quickly, but made her lover suffer longer. I think the axe is more plausible as the neighbours would hear a gunshot, and if was a lumberman, he would know how to use an axe!
Like I said, this is a family legend, so I have no idea if it is true, or if part of it is true, or if it is total fiction. Also don't know if the relative is supposed to be the husband or the wife.
But if you do find anything, I would be fascinated to hear!