We present the characterization of the three T type candidates (S Ori 70, S Ori 73, and S Ori J053804.65-021352.5) lying in the line of sight towards σ Orionis (˜3 Myr, ˜352 pc, solar metallicity) by means of near-infrared photometric, astrometric, and spectroscopic studies. H-band methane images were collected for all three sources using the LIRIS instrument on the 4.2 m William Herschel Telescope. J-band spectra of resolution ˜500 were obtained for S Ori J053804.65-021352.5 with the ISAAC spectrograph on the 8 m Very Large Telescope (VLT), and public low resolution (R˜50) JH spectra obtained with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope (HST) were employed for the spectroscopic classification of S Ori 70 and 73. Accurate proper motions with a typical uncertainty of ±3 mas yr^{-1} were derived using ancient images and new data collected with ISAAC/VLT and WFC3/HST. The three objects were spectroscopically classified as T4.5 ± 0.5 (S Ori 73), T5 ± 0.5 (S Ori J053804.65-021352.5), and T7^{+0.5}_{-1.0} (S Ori 70). These spectral types agree with the H-band methane colors. The proper motions of S Ori 70 and 73 are larger than that of the cluster by >4 σ. The proper motion of S Ori J053804.65-021352.5 is consistent with a null displacement during the time interval of 7.03 yr.