Turks mourn secular champion
"Turkey needs political stability and then this happened… a murder reminding of the troublesome old days," Mr Gul said.
Earlier this year, Mr Hablemitoglu gave expert witness at the trial of an Islamic brotherhood charged with plotting to overthrow the secular state.
Violent past
The last three decades of Turkish history have been dotted with politically motivated assassinations.
Assassinations sometimes featured in fighting between right- and left-wing groups in the 1970s, which ultimately triggered a 1980 military coup.
Killings continued through the 1980s and 1990s. Targets included several Kurds, but their attackers have never been caught.
In 1993, an investigative journalist, Ugur Mumcu, was murdered in a car bomb attack after researching connections between the state and organised crime.
The state attracted widespread suspicion of involvement in some of those killings.
But the strong army presence at Mr Hablemitoglu’s funeral, correspondents say, was a gesture of loyalty to the secular political system.