10:36 AM PT -- Police eventually found Soules at a residence but it took hours for them to get a search warrant ... this according to KWWL TV. It will therefore be difficult for prosecutors to prove he may have been under the influence at the time of the crash since hours passed before he was spotted.

10:10 AM PT -- We're told Chris just posted bond and will be released shortly.

7:45 AM PT -- Soules is in court now for his arraignment. TMZ has obtained documents in which police say he was in possession of alcoholic beverage containers at the time of the crash. Soules was apprehended after witnesses near the scene of the crash ID'd him and called police.

Chris is being held on a $10,000 cash bond.

'Bachelor' Chris Soules is in custody after allegedly slamming into a tractor, killing the driver and then fleeing the scene ... TMZ has learned.

The incident happened in Iowa Monday at 8:20 PM. According to docs, Chris was driving a Chevy pickup and rear ended a John Deere tractor, sending it into a ditch. The driver was taken by ambulance to a hospital, where he died.

Soules, who appeared on "The Bachelor" for season 19 in 2015, is in custody and we're told he received medical attention.

Soules was booked on the charge of leaving the scene with a death.