Margaret Trudeau gave credit to her former husband, the late prime minister Pierre Trudeau, on Tuesday after a judge ruled her rights had been violated and threw out alcohol-related charges against her.

Ontario Court Judge Lise Maisonneuve ruled police officers violated Kemper's rights to counsel and protection against unwarranted detention when she was pulled over on suspicion of impaired driving on May 30, 2004.

Margaret Kemper leaves the Ottawa courthouse following an appearance in October (CP Photo/Tom Hanson)

Maisonneuve also said police compromised Kemper's right to a fair trial.

Telling reporters she was relieved by the decision, Trudeau praised the role her first husband played in creating the Charter of Rights and Freedoms.

Trudeau died in 2000, 18 years after the ground-breaking charter came into effect. The Trudeaus divorced a couple of years later. Margaret Trudeau remarried, but is now divorced from her second husband, real-estate developer Fried Kemper.

• FROM JULY 22, 2004: Margaret Kemper charged with impaired driving

After Margaret Kemper was pulled over 18 months ago, a breathalyzer test revealed her blood-alcohol level was 107 milligrams of alcohol per 100 millilitres of blood, the court was told. The legal limit is 80 milligrams.

Kemper's lawyer, Michael Edelson, argued his client should not have been pulled over in the first place.

He said the officer had no radar, and so wouldn't have been able to tell if she were speeding.

Edelson said Kemper was also denied access to her choice of lawyer.

Police phoned the lawyers themselves, got voice mails, then didn't tell Kemper she could have left messages. Edelson said Kemper had to choose a lawyer from a list provided to her by the police.

The Crown had argued that her right to counsel was honoured "within reason."

A prosecutor had told the court that the arresting officer followed Kemper's vehicle after she passed him at a stoplight and that he timed her for several blocks.