We seek to understand how the technical definition of a Lehmer pair can be related to more analytic properties of the Riemann zeta function, particularly the location of the zeros of ζ (s). Because we are interested in the connection [4] between Lehmer pairs and the de Bruijn-Newman constant Λ, we assume the Riemann Hypothesis throughout. We define strong Lehmer pairs via an inequality on the derivative of the pre-Schwarzian of Riemann's function Ξ(t), evaluated at consecutive zeros:Theorem 1 shows that strong Lehmer pairs are Lehmer pairs. Theorem 2 describes PΞ (γ) in terms of ζ (ρ) where ρ = 1/2 + iγ. Theorem 3 expresses PΞ (γ + ) + PΞ (γ − ) in terms of nearby zeros ρ of ζ (s). We examine 114 661 pairs of zeros of ζ(s) around height t = 10 6 , finding 855 strong Lehmer pairs. These are compared to the corresponding zeros of ζ (s) in the same range.