Iliass Tahiri, 18, died on July 1, 2019 at Tierras de Oria detention centre in the southern Almeria province as security staff strapped him to a bed, using a procedure denounced by rights groups as dangerous.
Police opened an inquiry at the time but the case was closed after a judge ruled it “accidental” death.
However, CCTV footage of Tahiri's last moments in which he shows no signs of violence — a requisite for authorities to resort to such a restraint — was leaked to a Spanish newspaper.
“If you see the video, you'll never believe it was accidental as the judge said,” his brother Anass Tahiri, 22, told AFP.
“The video shows how they killed him. It's murder,” said Anass, whose family has lodged an official appeal against the case's dismissal.
Published by El Pais, the footage emerged as global protests raged following the death of George Floyd in the US when a policeman knelt on his neck.
The video's authenticity has been confirmed by a spokeswoman for Ginso, the private company managing Tierras de Oria.
Within a week of its publication, the Spanish ombudsman's office called for the abolition of such procedures in juvenile detention centres.
On June 18, the Almeria public prosecutor's office asked for the case to be reopened, denouncing as “illegal” the protocol for using such restraints.
Tahiri's case centres on mechanical restraint — strapping a person to a bed so they can't hurt themselves or anyone else — but can only be used if they are agitated, aggressive or violent.
In the video, six men roughly wrestle Tahiri on to a bed face down, at one point kneeling on his buttocks to tighten a strap around his waist, eventually realising he's no longer breathing.
Tahiri, who arrived in Spain in 2017, was placed in juvenile detention over “some problems in the street”, his brother told AFP.
He had been at Tierras de Oria for two months when he died.
The day before, the teenager was visited by his mother and told her he'd been subjected to threats and abuse, Anass recalled.
“He wanted her to get a lawyer to get him out because he'd reached the point that he'd rather be in prison than in that centre,” he said, adding that his brother had been on suicide watch.
In a statement to AFP, Ginso said “the need for the restraint procedure was demonstrated (during the investigation) as was its correct application by staff who complied scrupulously with the protocol,” saying its use was “exceptional” and only undertaken with the “minimum necessary force”.
But Andalusia's Human Rights Association (APDHA) says mechanical restraint is “standard practice” in juvenile centres, where it is often used for discipline or punishment.
“What the video shows is a grossly disproportionate use of force given Iliass' attitude, involving completely unnecessary aggression and violence when he was restrained,” APDHA's Francisco Fernandez Caparros told AFP.
“Clearly his death occurred while they were applying the restraints… it was this situation of stress and violence that killed him,” he said.
Two other youngsters have died after being restrained: one in Madrid in 2011, and another in Spain's Melilla enclave in 2018.
Ombudsman Francisco Fernandez Marugan called on the government to change the law.
“A swift and radical decision is needed that will end the use of mechanical restraints once and for all,” he said.
“Nobody else must die in these circumstances in Spain.”
The Almeria public prosecutor also ordered that all such restraints be “immediately” suspended.
The restraint protocol puts youngsters “at serious unjustified risk”, and where that results in injury, those responsible for approving such procedures will be held criminally liable, it said in a legal document.
Contacted by AFP, the regional justice ministry declined to comment on the prosecutor's statement.
But a spokeswoman said it would “respect and abide by” all judicial decisions.
The closing of the Tahiri case “is currently being appealed,” she said.
According to Andalusian opposition lawmaker Maribel Mora, the regional government did not hold an inquiry after Tahiri's death or check how the procedure was being used in centres under its jurisdiction.
In 2016, the Council of Europe's Committee for the Prevention of Torture visited Tierras de Oria and denounced its restraint procedure as a “disproportionate use of force”, urging regional governments to halt the practice, Mora told AFP.
Despite the call, mechanical restraints were used 360 times in the region's 16 juvenile centres in the following two years, official figures show.
“Whether or not they reopen the case, it is clear something is going very wrong and the (regional) government needs to respond and take responsibility for this,” Mora said.