Arson is defined as a crime 'of moral turpitude' by the US authorities. That means that, in the first instance, the US Embassy MUST refuse to issue him with a visa. They have no discretion whatsoever; the US Immigration and Nationality Act imposes an automatic ban upon him entering the USA.
However he can then ask that his visa application be transferred to Washington as an application for a 'waiver of permanent ineligibility'. The MINIMUM additional processing time is 6 MONTHS but the actual time taken to hear the result of such an application is often far longer. (Someone posted, here on AB, to say that her husband had to wait 15 months to find out whether he could be granted a waiver after two offences of driving without insurance; his application was eventually refused).
So it's almost certainly too late for your friend to get a visa for travel this year. He needs to apply now for travel in 2017.