The brutal rape and murder of the popular high-school student as she walked home after a night out with friends in the quiet Madrid suburb of Algete on April 20th, 1997, had shocked the local community and made headlines across Spain.
Eva was raped, stabbed in the back and then dumped in scrubland near a roundabout on Madrid's M-100 highway and the police made it a priority to find her killer, pursuing more than 100 lines of inquiry in the intervening years.
Police initially took DNA samples of dozens of men in the area including relatives, friends and acquaintances of Eva and her family but to no avail.
Repeated appeals had over the subsequent years done little to further investigations until three years ago when advances in DNA profiling matched semen found inside her body to someone likely to have his origins in North Africa.
Then in September after exhaustive comparison to more than 2000 samples of DNA taken during the investigation alongside a crosschecking of all those of Maghrebi origin known to be in the area in 1997 the police came up with a gentic profile that led them to their suspect.
The accused is reported to have lived for a short time with his brother in Algete around the time of Eva's murder and worked in construction where he may have come across Eva's father, who had a crane company.
Un perfil de ADN obtenido en septiembre ha sido crucial para localizar en Francia al presunto asesino de Eva Blanco https://t.co/PC0A8JejCQ— Ministerio Interior (@interiorgob) October 2, 2015
On Thursday a 52-year-old man Ahmed Chelh was arrested on a European Arrest Warrant in Pierrefontaine-les-Varans, a town in the Franche-Comté region of eastern France near the Swiss border.
The man, of Moroccan origin with Spanish nationality was married with children and had left Spain in 1999.
Eva's parents were informed of the arrest on Thursday bringing an end to 18 years of anguish.
"It was a very emotional moment; the captain also got emotional when he told us about the arrest. He started to cry," Olga Puig, Eva's mother, told El País.
"Now I hope that justice will be done and that this man pays for everything he did to my daughter.
"It looks like God has heard me and given me some joy after so many years of suffering,"
Both her and Manuel Blanco joined the Interior Minister at a press conference on Friday to congratulate police on the arrest.