Authorities arrested three Texans in Ohio last week after an investigation revealed that the trio attempted to mail large amounts of fentanyl from Ohio, police said.

Police arrested Anthony Robinson, 32, Barbera Wilson, 21, and Darrius Lewis, 29, and charged them with conspiracy drug possession with intent to distribute controlled substances, according to a tweet from the U.S. Attorney’s Office of the Northern District of Ohio.

The Dallas Morning News reported that authorities began their investigation Monday after discovering that three “suspicious people” checked in to a Red Roof Inn in the Toledo area.

Police reportedly watched the three suspects leave and enter their motel rooms on Monday and Tuesday, and witnessed Robinson and Wilson drive to a Toledo post office Tuesday in separate cars.

Robinson reportedly walked into the post office carrying a package while Wilson returned his rental car. Then, Wilson returned to the motel in Robinson’s car.

After obtaining a warrant to search the motel rooms and the post office, police found one kilogram of the drug at the post office, and found another half-kilo and $8,500 in cash from the motel room where the suspects stayed, the Toledo Blade reported.

The drugs had an estimated street value totaling about $1 million, authorities said.

U.S. Attorney Justin Herdman of the Northern District of Ohio said in a statement that the drug bust was enough “to kill everyone in Toledo several times over.”

When authorities questioned the three suspects, Robinson and Wilson claimed that they were half siblings who drove to Ohio from Texas for a wedding and a proposal dinner, the criminal complaint says.

Lewis claimed that he flew to Ohio from Houston, according to the complaint.

Robinson, Wilson, and Lewis are being held at the Lucas County Jail in Ohio, police said.