"An arrest warrant in rem differs from a seizure order/warrant because it is issued after the filing of the civil forfeiture action by the court. Once issued and served, the property is either actually or constructively seizued, thereafter vesting the court with in rem juristidiction over the res.
There is no requirement that the magistrate conduct a probable cause hearing before issuing the arrest warrant in rem, as it is merely a ministerial duty that may be performed by a clerk.
However, the use of the arrest warrant in rem has limited applicability in state forfeiture practice, as only two states authorize its use in their state forfeiture procedure."
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and this...
"Advantages of civil in rem forfeiture include immediate possession of the property. The law enforcement agency obtains actual or constructive possession of the property and retains custody on behalf of the court pending the resolution of the forfeiture action. There is no criminal conviction requirement, and the lower civil burden of proof applies. Hearsay evidance may be used to establish probable cause."