For your information. I've found an interesting site for my country (Scotland).
Homicide in Scotland during 2012-213. Alcohol or drugs has a significant relationship.
"In 2012-13, there were 62 cases of homicide involving 62 victims. This represents a decrease of 31 victims from 2011-12. There were 83 persons accused of homicide in Scotland in 2012-13.
Over the last 10 years, the most common method of killing has consistently been with a sharp instrument. In 2012-13, of the 51 persons accused of homicide, for whom the alcohol and drug status was known, 71% were reported to have been drunk and/or under the influence of drugs at the time."
The Scottish Government site also provides the base data sets that can be browsed and filtered.
"For 47 of the homicide victims recorded in 2012-13, the main accused was known to them either as an acquaintance (56%), a partner or ex-partner (15%) or a relative (7%). Seven victims were killed by a stranger, 11% of all victims. For the remaining 11% of victims in solved cases, the relationship of the main accused and victim was unknown."
Having this type of data on hand is an essential tool to aid your teaching.