The violent crime rate against the elderly has declined 50 percent since 1973, the government said yesterday.

Elderly Americans are half as likely as younger people to become the victims of crime. However, when crimes are committed against elderly victims, the crimes tend to be more serious, according to the study by the Justice Department's Bureau of Justice Statistics.

From 1980 through 1985, elderly violent-crime victims were more likely to face offenders with guns than were younger victims -- 16 percent to 12 percent.

The study found that 20 percent of the victims aged 75 or older required medical treatment after a serious crime, such as a robbery, assault or attempted rape, compared with 11 percent of violent-crime victims who were 65 to 74 years old and 13 percent of those younger than 65.

But overall, those 65 and older had the lowest victimization rates of any age group in the U.S. population starting with age 12. The 1985 violent crime rate against the elderly was 50 percent lower than the rate for 1973, the study concluded.

The average number of violent crime victims per 1,000 people was six for those who were at least 65; 11.3 for those from ages 50 to 65; 34 for those from 25 to 49; and 67.5 for those 12 to 24.