“Motive” 10 p.m. Monday

If you were reading a generally competent mystery novel, would you fight the temptation to flip to the end to learn the motive if you already knew the culprit?

Let’s put it this way: There have been some great mysteries where you knew the killer from the get-go, but they are by far the exception to the rule, and with good reason: We may care about why a murder took place, but what keeps our interest, nine times out of 10,000, is who did the deed.

ABC calls its new Canadian import “Motive” because that’s what the mystery is. Each episode starts by identifying the killer and the victim, so instead of being a whodunit, “Motive” is a “whydunit,” which, except for the appeal of the show’s star, amounts to a “whocares.”

Created by Daniel Cerone (“Dexter,” “The Mentalist”), “Motive,” premiering Monday, stars Kristin Lehman as homicide Detective Angie Flynn, a street-smart single mom who works with Detective Oscar Vega (Louis Ferreira) to solve murders, like that of a popular high school teacher in the premiere episode played by former New Kid on the Block Joey McIntyre. The killer is a high school loner named Tom (Tyler Johnston) who gets his kicks by “creeping” — breaking into people’s homes with his stoner friend Willie (Iain Belcher) just for the sake of breaking in.

It doesn’t take very long to figure out how the killing occurred, once the camera shows Tom hiding in the attic of the teacher’s home, which is to say, it’s kind of a problem when the motive of the premiere episode of a show called “Motive” is no motive at all.

The show’s second episode, airing May 23 when “Motive” slips into its regular Thursday time slot, turns on why a popular mayoral candidate killed his teenage baby-sitter in a hit-and-run. Here, the motive is a bit less transparent, which pulls us in just so we can see the cocky politician get his predictable comeuppance.

Tthe best thing about “Motive” is Lehman. She’s believable as a smart city cop the way Maria Bello was in the short-lived American version of “Prime Suspect” on NBC. She’s pretty much the one reason you may stick with an entire episode of “Motive” in spite of knowing the killer’s identity.