Laws and law enforcement for actions whose illegality is controversial (the case of 'honor killing')

Repugnant transactions and actions are sometimes banned with the full force of the law: consider  e.g. narcotics trafficking in the U.S., where our prisons are full of people convicted of drug crimes.   But sometimes, a legal ban comes with just a slap on the wrist: e.g., also in the U.S., prostitution is illegal almost everywhere, but mostly treated as a misdemeanor, not a serious crime. 

The punishment may not always fit the crime, but it tells us something about how legislators view the seriousness of the crime. 

So I was struck by the first sentences of this NY Times story about an "honor killing" in Iran:

A Daughter Is Beheaded, and Iran Asks if Women Have a Right to Safety
The so-called honor killing of a 14-year-old girl in Iran has shaken the country and forced an examination of its failure to protect women and children.

"Before he beheaded his 14-year-old daughter with a farming sickle, Reza Ashrafi called a lawyer.

"His daughter, Romina, was going to dishonor the family by running off with her 29-year-old boyfriend, he said. What kind of punishment, he asked the lawyer, would he get for killing her?

"The lawyer assured him that as the girl’s guardian he would not face capital punishment but at most 3 to 10 years in jail, Mr. Ashrafi’s relatives told an Iranian newspaper.

"Three weeks later, Mr. Ashrafi, a 37-year-old farmer, marched into the bedroom where the girl was sleeping and decapitated her.