The top prosecutor in the northern Mexico state of Chihuahua says it does not appear a drug cartel was behind the shooting of the former police chief of the border city of Ciudad Juarez.

Prosecutor Jorge Gonzalez told local media Monday that a man confessed to shooting former police chief Julian Leyzaola because of a personal grudge.

The suspect had three past arrests for auto theft and authorities are investigating if he was linked to any of Ciudad Juarez's street gangs.

But Gonzalez said Friday's attack did not match the more deadly techniques drug cartels use.

Gonzalez said the shooter claimed there had been a conflict between his sister and Leyzaola, a tough cop who also served in Tijuana.

The prosecutor said Leyzaola is recovering from his wounds.