The parents of a 17-year-old girl who was killed nine years ago in the UK have been convicted of her murder and jailed for life.

Iftikhar Ahmed and his wife Farzana were told on Friday that they were to serve a minimum of 25 years in prison after a jury at Chester Crown Court found them guilty of their daughter Shafilea’s murder.

Shafilea was suffocated with a plastic bag at the family home in Cheshire, northern England on September 11, 2003, because her parents felt that her choice to lead a “Western” life had led to her family being “shamed”.

“There is always a trigger. In the case of Shafilea, the abuse she suffered was motivated by her parents’ desire to control her. To make her to conform to their interpretation of Pakistani culture. They tried to control her, to force her into marriage, and to prevent her from expressing herself,” said Detective Superintendent Geraint Jones, at a news conference after the sentencing.

“When this failed, they murdered her. A vile and disgraceful act, against their own daughter, a murder of someone they should’ve been very proud of,” he said.

Jones led the inquiry for Cheshire Police from 2003 until 2010.

Shafilea’s parents denied any wrongdoing and in one interview her father Iftikhar was quoted as saying he would never harm his daughter.

“Would we kill our own daughter… Never, I couldn’t even dream of it,” he said.

After Shafilea’s decomposed remains were discovered in the River Kent in February 2004, however, her parents changed their tone.

“The times I did meet them they were polite and very unchallenging I would describe them as. But as the investigation progressed and as the evidence built, particularly once we found Shafilea’s body, their attitude changed and they became aggressive,” Jones said.

“They, in their own minds thought they could use the media to point the finger elsewhere as we’ve heard in court. But behind it all, we knew, within that house there was torture, there was domestic abuse,” Jones said.

During the trial, Aleha, Shafilea’s sister, testified that her parents repeatedly attacked and abused Shafilea as she grew up. She said that Shafilea had grown increasingly distant from her parents’ traditional lifestyle.

“The word ‘shame’ has been heard many times during the course of this trial in at least three languages. And the evidence has shown that cultural factors were literally at the heart of the Ahmeds’ abuse of Shafilea,” said Helen Morris, advocate for the Crown Prosecution Service.

“Why did they abuse Shafilea, why did they kill her? Put simply it was because she challenged their regime and refused to conform to their expectations. She wanted to choose how she lived her life and who she married – choices that are fundamental freedoms for any citizen of the United Kingdom,” she said.

At the news conference, the police and Crown Prosecution Service said they would review conflicting evidence to see if any further action should be taken.

Diana Nammi, a women’s rights activist in the UK, told Al Jazeera that there were at least 3,000 reported cases of ‘honour’-related violence and killings in the country in 2010.

“This is a huge problem. It is not about one family or two families, it’s about the whole community, it’s about 3,000 at least … which we believe are just the tip of the iceberg [because] they are the women who had the courage to come forward and seek help,” she said.

“There are so many who do not have confidence, they are scared, they are worried about their families and their reputation within the community.”