Police in Brazilian city Rio de Janeiro on Thursday arrested a 17 year old and charged him with killing Ana Cristina Johannpeter, a 58-year-old Brazilian who was a showjumping champion in the 1988 Seoul Olympic, during a robbery in the upscale Leblon district.

Johannpeter died on Wednesday night, after being shot in the head by two assailants who escaped by bicycle. Johannpeter's daughter said that the killers shot her mother because she was taking too long to hand over her watch.

The former athlete was married to top industrialist Germano Gerdau Johannpeter, vice-president of the powerful Gerdau group.

Police said the youth's nerves made him shoot, and that he was arrested in the Cruzada Sao Sebastiao slum, close to the scene of the robbery. The police are looking for two others in connection with the assault. The three are known as the bicycle gang, and have been active in the Leblon and Ipanema neighborhoods in the rich south of Rio de Janeiro.