Before the 48-year-old Social Democrat committed suicide on Thursday morning, he made a macabre phone call to the police in Zug: “I am going to die. You will find me in Ticino, on Via ai Monti in [the village of] Ronco sopra Ascona.”
He then pulled the trigger and shot himself in the head, Blick newspaper reports.
The police found him dead at 10am, just as the morning session began at the Zug parliament. Colleagues said they were surprised when he did not show up or call to announce his absence. “That was not his style,” said Barbara Gysel, a party colleague.
Deliberations on the 2012 budget were then interrupted by the tragic news from Ticino.
An advocate of stricter gun control, Lehmann encouraged voters last February to vote in favour of a Swiss referendum initiative aimed at tightening regulations governing the possession of weapons.
On his Facebook page he wrote: "From a purely pragmatic standpoint, I am of the opinion that every suicide carried out with a firearm is one too many."
Suicide prevention was one of the main reasons put forward by the supporters of the ultimately unsuccessful initiative given the fact that Switzerland has the highest amount of suicides per capita in Europe. In fact, suicide accounts for 90 percent of the country's firearm-related deaths, says the Group for a Switzerland without Arms.
Lehmann was a single man, held a senior position at Credit Suisse and led the Aids-Help foundation in Zug. He was to become president of the Zug parliament in the spring of 2012.
Even though the owner of the house he rented overlooking Lake Maggiore said he always appeared cheerful, one of his colleagues told a different story.
“A year ago he sought my advice,” said former councillor Malaika Meli-Hug, who left politics in 2006 due to depression. She told newspaper Blick that Lehmann confessed he suffered from depression and was taking medication to combat its effects.