What civil asset forfeiture is
In a civil forfeiture case, the government sues the property itself rather than the owner. The legal standard for the state to keep what it took is far lower than what is required for a criminal conviction.
In Texas, prosecutors only need to prove by a preponderance of the evidence that the property was used in, or proceeds from, certain criminal activity. That is why so many forfeitures go unchallenged: most owners do not realize they have a right to fight, and the deadlines are short.