Need a federal lawyer after a warehouse search

Got a call from my brother this morning that none of us were ready for. Federal agents showed up at his warehouse with a warrant and took computers, phones, and boxes of invoices. He runs an electronics resale business, and investigators apparently think some payments and shipments were tied to a larger fraud case involving sellers in several states. He hasn't been arrested, but an agent left a number and wants him to come in for an interview next week. His regular business attorney admits this is way outside his lane. Where do we find a federal criminal lawyer who deals with cases like this?