Mexico City, Jun 28 (EFE).- Authorities here expressed regret Wednesday over the execution of Mexican citizen Angel Maturino Resendiz, the notorious "Railroad Killer," at a prison in Huntsville, Texas. Resendiz, sentenced to death in 2000 for the rape-murder of a Houston doctor but also believed responsible in a dozen other slayings, was executed Tuesday night by lethal injection "despite medical evidence about the severe mental disturbances he suffered," the Mexican foreign ministry said in a communique. A Texas court ruled last Wednesday that Resendiz, who asked for forgiveness before being executed and said he deserved his fate, was mentally competent...