The Illinois State Police, Forensic Sciences Command (FSC), has used lasers in its seven operational laboratories for more than 15 years. The instrument found in most laboratories is the Coherent Innova 200 argon-ion continuous wave (Ar cw) laser purchased in July 1991. This is a water cooled Ar cw laser capable of 20 watts of light output at its peak performance. It produces six wavelengths with strong lines at 488nm and 514.5nm. The lasers are used primarily for examining untreated (inherent) latent prints, dye stained cyanoacrylate ester (CAE) treated latent prints, and zinc chloride treated ninhydrin-developed prints. The lasers have performed well and have been used in other fields. The laser used for comparison was a Spectra-Physics Millennia Xs, a diode-pumped solid state cw laser with only one green line at 532nm. The study included data on the Millennia's ability to visualize marks, initial purchase cost, operating costs, environmental issues, heating-ventilation and air conditioning issues, operator training, maintenance, and footprint. The Millennia performed as well as the Innova for latent print examinations involving inherent luminesce [sic], luminescent powders, Rhodamine 6G, zinc chloride stained ninhydrin, Ardrox, DFO, and MRM10 when the correct viewing and photography filters were selected. Reduced operating expenses and installation and maintenance costs combined with high portability make the Millennia an attractive possibility for use in the laboratory. The study recommends that each forensic laboratory consider one of the Millennia series of lasers as a replacement option for large frame, ion, Ar cw lasers. Figures, bibliography, appendix