Gastélum was filming with two friends outside a fast food restaurant in Tres Ríos, in the northern city of Culiacán, on Tuesday evening when when two men on a motorbike drove up to him and one shot him at close range.
He had more than half a million followers on TikTok and mainly uploaded comedy videos.
It is not the first time a social media influencer has been killed in Mexico. Last year, 23-year-old Valeria Márquez was shot dead at a beauty salon while she was livestreaming on TikTok.
On the livestream, Gastélum and his friends were wearing bright orange coats and bags typically used by delivery drivers.
Local media reported that their outfits originally led police to believe that the victim was a delivery driver, but officials were later alerted to his identity.
Police and forensic experts cordoned off the area and are examining the cartridge casings and CCTV footage for any clues.
No arrests have so far been made and the two people on the motorbike fled the scene.
It is not yet clear whether Gastélum had received any threats.
On his Instagram account he often shared pictures of his travels and nights out, or posing in front of luxury cars.
In one of his posts, he could be seen at the grave of Leobardo Aispuro, an influencer known as “El Gordo Peruci”.
Aispuro was shot dead in December 2024, in a killing which police said may have been linked to the rivalry between two warring factions of the Sinaloa cartel.
Violence in the state of Sinaloa, of which Culiacán is the capital, has spiralled since the two factions – Los Chapitos and La Mayiza – fell out in September 2024.
