A US teenager has been shot dead by local police in the southern Mexican state of Oaxaca in yet another shocking case of police abuse and brutality. The 16-year-old victim – identified only as Alexander – was killed on Tuesday night after he went out to buy soda, according to media reports. Details of the shooting remain unclear. News agency Quadratín said Alexander was shot at from a patrol car in an attack that injured a friend. The newspaper Reforma quoted a family member, who said Alexander was riding on a motorcycle with a 15-year-old boy at around 10.50pm and was chased by police. “They were in a petrol station buying a soda. They started to shoot, and because these 15- and 16-year-old boys were scared, they ran,” a cousin, Dulce Darián, told Reforma. “They didn’t give them the option to stop or take off their face masks. They simply started to shoot and they shot him in the head. Alexander died instantly because the police didn’t want to give him first aid.” Prosecutors in Oaxaca have opened an investigation into the shooting in the town of Acatlán de Pérez Figueroa, but provided no details, according to a brief statement. The municipal government expressed regret on its Facebook page “for the incident that occurred last night” and said it had turned over evidence to state investigators. But it also tried to pass off the shooting as an accident, saying it was not carried out “in bad faith or to harm the community”. They also showed sly support for the police with the illegible hashtag: #Thehistoryofthe[police]forcespeaksforitself. The municipality’s statement reflected a tendency for Mexican authorities to blame the victims of violence for the crimes and aggressions committed against them – including police brutality. “They want to incriminate Alexander to justify the vileness of their actions,” tweeted Javier Valdivia, a native of Acatlán de Pérez Figueroa. Video uploaded to Twitter showed a woman presumed to be Alexander’s mother shouting at the police: “My son wasn’t bad, he didn’t smoke, he didn’t drink, my son had a dream … They’re not criminals, they’re kids. And I’m not going to believe that these arseholes confused them [with someone else].” Local press reports said Alexander was staying with his grandparents in the town where he was shot. Relatives say he was born in North Carolina to Mexican parents. The killing comes just days after a wave of national indignation over the death of Giovanni López, a construction worker in western Jalisco state, who was forcibly detained by municipal police for not wearing a mask and found dead the next day by his family. Subsequent protests against police violence were themselves met by further police violence. About 80 people were seized by plain-clothed police officers on their way to a demonstration in the city of Guadalajar, and held for for hours. The victims said they were beaten, threatened with death, and eventually dumped in isolated areas. Evidence collected by human rights groups suggested that security forces in Mexico are routinely responsible for abuse, torture, and extra-judicial killings. “It’s really a volatile mix of a lack of training, an inability to attract quality people and a lack of oversight,” said Falko Ernst, senior Mexico analyst with the International Crisis Group. “There’s also an endemic culture of corruption and collusion.” With reporting from the Associated Press