All aspects of the planning, execution and his blasé attitude combined with the scarce details of his mental state is suggestive of someone whose capacity for rational thinking is impaired.
However, his actions were completely reckless and could have caused a serious threat to not only his own life but to others if there had been a gas explosion.
The damage to the grade 2 building is not insignificant either (third oldest synagogue too).
Whilst the perpetrator obviously has issues, these have to be seen in proportion to the severity of the act.
This was no ordinary or disused building, a fact that he knew. He specifically targeted a building of another faith and wanted to see its destruction.
Attacks on synagogues and mosques are on the rise which presents a number of challenges to the authorities.
It has to be of increased concern and cannot be dismissed lightly even where the attacker(s) mental capacity is diminished.