A lorry on the M1 near Northampton had its windscreen smashed after someone threw an object at it from a bridge.
The HGV driver saw a person standing on a bridge at junction 16 appearing to take photographs as they travelled northbound at around 11.15am on Thursday, October 17.
As his vehicle passed the bridge its windscreen was smashed by an item, possibly a stone, thought to have been dropped from the bridge, according to police.
Fortunately the driver was not hurt and was able to safely pull over shortly afterwards, but police are investigating the incident as criminal damage to a vehicle endangering life.
Officers would like to hear from anyone who may have seen the person on or near the bridge before or afterwards, who witnessed the incident or who has information about it.
Anyone with information should call Northamptonshire Police on 101, or Crimestoppers anonymously on 0800 555111.