Here are a few more:

Both men were killed by a bullet that entered the head from behind.

The first name of Lincoln's private secretary was John, the last name of Kennedy's private secretary was Lincoln.

Both assassins were Southerners who held extremist views.

Both assassins were murdered before they could be brought to trial.

A Licoln staffer Miss Kennedy told him not to go to the Theater. A Kennedy staffer Miss Lincoln, told him not to go to Dallas.

Later, QD.