Elisa Kelly did not want her teenage son, Ryan, or his friends to endanger their lives by drinking and driving. So she decided to let him have a 16th birthday party at home, where she would supply the beer, confiscate all the car keys and supervise a nightlong sleep-over.

Today she begins a 27-month jail sentence imposed by courts in Virginia – where drinking is banned for people under the age of 21 – for “contributing to the delinquency of minors”.

Although the punishment was reduced from eight years on appeal, it is the harshest anyone can remember locally for such an offence. George Robinson, her former husband and the boy’s stepfather, has been sentenced to the same jail term.

Yesterday, speaking to The Times on her last day of freedom, Kelly said: “I’m getting more and more scared about going to jail. No one got in a car and drove anywhere, no one got hurt. I really don’t think I deserve this.”

The case reflects the strong puritanical impulse of American society, which seeks to restrict gambling, pornography and drinking even though statistics and anecdotal evidence abound that many of the young routinely gorge themselves on all of them.

Pressure groups point out that about 5,000 American teenagers die from alcohol-related causes each year. The Drug-Free Alliance has started a public awareness campaign entitled “Parents who host, lose the most – don’t be a party to teenage drinking”.

Prosecutors had demanded a 90-day sentence for the offence in August, 2002, but County Judge Dwight Johnson, who has since retired, decided to make an example of the couple because a teenage girl from Ryan’s high school had died in an unrelated drink-driving accident a month earlier.

Kelly’s dilemma on that night five years ago is familiar to parents everywhere. “Kids have always tried to drink, probably since the beginning of time. We agreed to let Ryan have a party on condition that everyone gave up their car keys and stayed over for the night,” she said. “I’m very against kids driving after drinking, but they were responsible – most of them were athletes who I knew as a sports coach.”

She spent $340 (£173) on alcohol for the event for 60 teenagers, was present throughout, and did not drink a drop of alcohol herself. But the party, in a remote corner of Virginia near Earlysville, was raided by police who were acting on a telephone tip-off they received at 11pm. The youths were reported to have yelled “Cops!” and scattered into woods.

Police rounded up 16 teenagers, seven of whom were found to have no alcohol in their system, while the other nine were all below the legal limit at which a person is classed as intoxicated.

Since then Kelly, 42, has divorced, and her house has burnt down. She claims to be facing bankruptcy after spending more than $150,000 (£76,000) on legal fees, contesting her sentence all the way to the US Supreme Court on the ground that the police raid violated her constitutional rights against unreasonable searches and seizures.

Her son, apparently wracked by guilt, and, she says, picked on by teachers for his role in the affair, dropped out of school. If she serves her full sentence, she will miss seeing her other son, Brandon, complete his final two years in high school.

Kelly believes that she and her exhusband were treated unfairly because of the political ambitions of James Camblos, the county attorney who prosecuted the case. “He wanted to make an example of us and get some publicity,” she said.

But Mr Camblos, who has made curbing underage drinking a cornerstone of his reelection campaign this year, insists that it was the worst such case that he has dealt with in 15 years.

He said: “The facts were outrageous. Prosecution was absolutely appropriate. Not only were they serving alcohol to 15 and 16-year-olds, they misled parents who called to ask about alcohol, and they tried to get the kids to cover it up after police got there.”

Kelly yesterday was preparing to be driven to jail by her sons, after clearing out her rented apartment. “I’m having a ‘last supper’ tonight. The kids won’t be getting any alcohol, but I think I might have a drink.”

Drive at 15, fight at 17, drink at 21

— Most Americans can drive with a learner’s permit at 15 years and 6 months

— The minimum legal age at which Americans can purchase alcohol or drink it in a public place is 21. This law was passed in 1984 after a campaign by Mothers Against Drunk Driving

— Virginia is one of more than 20 states that forbid adults to serve alcohol to minors other than their own children or to allow under-age drinking in their homes except during religious ceremonies

— In Virginia, you can buy a rifle or shotgun at 18 and a handgun at 21. You can own a rifle or shotgun at any age.

— In Massachusetts and New Hampshire males can marry with the consent of a judge at 14 and females at 12 and 13 respectively. Residents of Mississippi can marry at any age with legal consent

— Americans can join the army at 17 with consent

— Selling cigarettes to anyone under the age of 18 is illegal in most American states

Source: US Government, Virginia State Police

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