Is there any risk in mentioning a new faculty as a potential advisor in you SoP? I am applying for a program and I know that there is a new professor in the department. He is a tenured faculty and had been for many years at another university before he moves to his new position. 

I like his work and had been following his publications for a while, and he just moved to this department. I was wondering if it's a common practice for the departments (in the US) to avoid assigning new students to new faculty or anything that would make the admission committee wary of admitting an applicant that wants to work with them. Is there any risk in mentioning a faculty so new to the department as a person of interest in my PhD application statement? On the other hand, is there any possible upside to that?
I don't see any negative aspects to such a request. If nothing else it shows that you have a focus on a particular area of research. But in the US it isn't really necessary, almost everywhere, to specify a doctoral research advisor so early. 

I assume that a "new, but with tenure" professor in a department is well respected everywhere. People are seldom hired "with tenure" otherwise. Most incoming professors have some, probably short, probationary period with at least a pro-forma grant of tenure. 

As to the suitability of the person as an advisor, you should also look at their history of producing PhDs. I assume he is experienced at that, and if not, then you should probably keep your eyes open before you jump.