The vehicles were suspected to have been stolen. Some 112 IDs were also alleged to have been found at the home.
Flying Squad's constable James Mwangi had on Thursday last week filled an application to retain the vehicles and continue with investigations.
The detective intended to establish, from police records, whether the vehicles have been reported stolen or used in criminal activities.
He also wanted to establish whether Mutheu and a man arrested at her home Johnson Karagu have been involved in robberies.
In an affidavit, Mwangi said he wanted to confirm the ownership of the vehicles with the NTSA and find out the whether the IDs were genuine.
But on Thursday he told the court that he does not intend to level charges against Mutheu and Karagu.
The officers who arrested Mutheu had been led to her home by a robbery suspect who claimed to have delivered four vehicles at the home.
But the vehicles he claimed to have taken to Mutheu's home were not at the compound.