Bogota police major Robert Mendez told reporters that the street shooting late on Monday was an "assassination perpetrated by a hitman."
"We reject the hypothesis of a robbery," said Mendez.
The 45-year-old engineer, whose identity was not initially made public by the French Embassy, was shot dead as he left a restaurant with a French colleague in Bogota's upscale district of Chapinero.
He was approached from behind. Only the Thales engineer and not his colleague was shot, said a police source quoted by the French news agency AFP, adding the engineer had been due to return to France on Wednesday.
Hosting defense exhibition
Bogota is currently hosting Expodefensa, a defense and security trade fair, attended this year by 269 exhibitors from 24 countries, including Thales.
The Paris-based aerospace and defense group expressed shock at the killing, saying the victim's colleague was "immediately supported by the relevant authorities and Thales management on the spot."
A team sent to Bogota was in "contact with local authorities and the diplomatic corps," a Thales spokesman added.
Widespread protest wave
Colombia is currently embroiled in widespread demonstrations against economic trends, a funding shortage for education and killings of community leaders by armed groups.
On Monday, President Ivan Duque's government accepted a request for exclusive talks from a strike committee comprising trade unions and civil society groups.
Colombia's unrest, which has claimed at least five lives, echoes protest over inequalities that has also swept Ecuador, Chile and Bolivia.