Photo/Illutration Jun Saito is sent to prosecutors from the Sayama Police Station in Saitama Prefecture on Dec. 27. (Hiroyuki Yamamoto)

HANNO, Saitama Prefecture--A 40-year-old man arrested in connection with a triple-murder was busted three times this year over damage to the victims’ car, police sources said.

But prosecutors could not indict him over the property damage because of insufficient evidence, according to the sources.

Saitama prefectural police are investigating the link between the property damage incidents with the murders, on suspicion the man held a grudge against the family.

Police found the three people dead at a house in Hanno, Saitama Prefecture, near Tokyo on Christmas Day.

Police arrested Jun Saito, 40, an unemployed man who lives nearby, that evening on suspicion of the attempted murder of William Ross Bishop Jr., a 69-year-old American citizen who lived in the house.

Saito is accused of striking Bishop on the neck and other parts of the body with a blunt object that caused a cervical spinal cord injury.

On the morning of Dec. 27, police upgraded his charge to murder and sent him to prosecutors.

Police are also investigating the deaths of Bishop's 68-year-old wife, Izumi Morita, and their 32-year-old daughter, Megumi, who lived in Tokyo’s Shibuya Ward, as murders.

According to investigators, the couple’s car had been scratched multiple times since summer last year while it was parked at their house. They reported the incidents to police and installed security cameras.

In January, a police officer on a stakeout caught Saito throwing a stone at the car, and he was arrested on suspicion of destruction of property.

But the case was dropped as prosecutors said there was no clear connection between the stone and the scratches on the car.

Prefectural police later arrested Saito two more times on similar suspicions based on security camera footage. Both cases were dropped due to insufficient evidence.

Bishop and his wife told police during the investigation that they had “no idea” why they were being targeted.

Saito never gave a clear explanation of why he had apparently attacked the car.