The defendant, a local resident identified only as Bernd W. due to German privacy laws, was indicted on five counts of murder and 18 counts of attempted murder for intentionally driving at pedestrians in a busy shopping area.
Investigators said he drank alcoholic beverages before the attack.
The people killed were a 45-year-old father and his 9-week-old child, and three women ages 25, 52, and 73. Prosecutor Eric Samel said the defendant intended to kill as many people as possible, German news agency dpa reported Thursday.
Dpa said that the defendant declined to testify at the start of the trial in the Trier regional court.