Ron was surprised that Percy was coming to him with this. He certainly wasn't one of the most senior Aurors and since Harry's death he had not been assigned to any of the murder cases which was apparently a good thing since they had now combined all the investigations because of their similarities.
Of course he was also surprised because he didn't know that Percy still talked to his ex-girlfriend or that Penelope's brother had died. "I-I didn't know that her brother had died, mate, I'm sorry. I mean, I haven't been assigned to any of the other cases but I'll certainly contact her if you'd like me to." He really felt a bit off balance by this request, mostly because he just never expected Percy to come to him instead of a senior Auror first, seeing how high up in the Ministry Percy was now.