DUBAI, United Arab Emirates (AP) — Iran has executed a second prisoner detained and convicted over crimes committed during the nationwide protests now challenging the country’s theocracy. Authorities publicly hanged him on Monday from a construction crane as a gruesome warning to others. The execution of Majidreza Rahnavard came less than a month after he allegedly fatally stabbed two paramilitaries after purportedly becoming angry about security forces killing protesters. It shows the speed at which Iran now carries out death sentences handed down for those detained in the demonstrations the government hopes to put down. Activists say at least 488 people have been killed since the demonstrations began in mid-September.