  The ferromagnetic (FM) nature of the metallic LaCo$_2$P$_2$ was investigated
with the positive muon spin rotation, relaxation and resonance ($\mu^+$SR)
technique. Transverse and zero field $\mu^+$SR measurements revealed that the
compound enters a long range FM ground state at $T_{\rm C}=130.91(65)$~K,
consistent with previous studies. Based on the reported FM structure, the
internal magnetic field was computed at the muon sites, which were predicted
with first principles calculations. The computed result agree well with the
experimental data. Moreover, although LaCo$_2$P$_2$ is a paramagnet at higher
temperatures $T>160$~K, it enters a short range ordered (SRO) magnetic phase
for $T_{\rm C}<T\leq160$~K. Measurements below the vicinity of $T_{\rm C}$
revealed that the SRO phase co-exists with the long range FM order at
temperatures $124\leq T\leq T_{\rm C}$. Such co-existence is an intrinsic
property and stems from competition between the 2D and 3D
interactions/fluctuations.

Strongly Correlated Electrons