"There is no indication alcohol or anything else was involved other than bad judgment," Canton Township police spokesman Sgt. Mark Gajeski said.
Dan Broughton of Woodhaven, a Detroit suburb, was driving, Gajeski said. State records show he had a number of traffic violations, including speeding and disobeying a stop sign in the Detroit enclave of Highland Park on Jan. 7. His failure to show a driver's license April 1 in Woodhaven led a judge to suspend his license for one month -- a suspension that began Wednesday.
Friends and family at Broughton's home declined to comment to an Associated Press reporter on Friday.
Authorities planned to release more information Friday on the victims and audio from a 911 report of the crash. Gajeski said he expected that the medical examiner's office would run toxicology tests. A message seeking comment was left with the medical examiner's office.
Investigators said the crossing had a gate and flashing lights that were working when the car approached. Police said the train, which was carrying about 170 people, typically travels about 67 miles per hour at the site of the crash. It broadsided the black Ford Fusion and pushed it about a mile down the tracks.
"There is no one to be charged," Gajeski said. "From witness statements and the video, the person just ran the gate."
The mother of 14-year-old Jessica Sadler said Thursday the girl was among those killed. Police previously said the young men killed also included an 18-year-old and a 20-year-old from Taylor and a 21-year-old from Stafford, Va.
No one aboard the train was injured, Amtrak said.
Last year, 119 people died nationwide in Amtrak accidents, usually when trains struck vehicles or pedestrians at railroad crossings, according to figures from the Federal Railroad Administration. Eleven people died in train accidents of all types in Michigan in 2008, according to Federal Railroad Administration data.