On Jan. 5, federal agents showed up at the couple’s Wall Street apartment with a search warrant.

At the apartment, investigators seized a plastic baggie marked “burner phone,” more than $40,000 in cash and more than 50 electronic devices, prosecutors said in court filings.

According to prosecutors’ filings, the couple chose to leave the premises while the agents searched. They asked to bring their cat, which was hiding under the bed.

As Ms. Morgan attempted to coax the cat out from hiding, she grabbed a phone from a nightstand, the filings said. She tried to repeatedly press the lock button, which prosecutors said appeared to be an attempt to keep investigators from being able to search it, and law-enforcement officials had to wrest the phone from her.