- “Just shoot me now, Sarge, and get over with. Don't torture me with that crap first.”— Locklear to Avery Johnson while hearing flip music
Though never mentioned during The Battle of Installation 04 or in the gameplay of Halo: Combat Evolved, Locklear was among the handful of survivors who fled in a Pelican when the Halo was destroyed. He, Lieutenant Elias Haverson, Staff Sergeant Avery Johnson and Petty Officer Second Class Sheila Polaski hid in the debris field until they met with John-117 and Cortana in their Longsword fighter. John-117 recognized that Locklear was in a state of shock from the destruction of the Halo, describing him as "a weapon with its safety permanently clicked off." Locklear was reluctant to accept John-117's command at first, but was eventually subdued by John's greater authority. He and John-117 then developed a closer working relationship over the course of OPERATION: FIRST STRIKE.
Locklear helped in the capture of the Covenant flagship Ascendant Justice, and was aboard when they returned to Reach. He then accompanied John-117 to the surface of Reach, where they rescued the SPARTAN-IIs who had survived the fall of Reach. At some point, he developed a crush on Polaski, who also returned his feelings. He was greatly saddened when she died in the Slipspace bubble caused by the Forerunner Crystal artifact.
He assisted the Eridanus Rebels with the repairs they made to the Ascendant Justice during its stay in the Eridanus secundus system. During the repair operation, Dr. Catherine Halsey entrusted him with the Forerunner crystal artifact. Halsey knew it was extremely dangerous as it would never allow John-117 to return to Earth directly through Slipspace and that there was chance it would fall into Covenant hands. She also knew that ONI and for that matter, all members of the service would place the rewards of the object's Slipspace effect above the risks, putting countless lives in jeopardy. She did not even trust the Spartans enough to relegate them with the crystal. She knew that Locklear would destroy it in an attempt to prevent another altered Slipspace battle like the one that had killed his crush, Warrant Officer Polaski, and she also hinted to him that the object's destruction was a necessity as if to guarantee he carried out her orders. However, Dr Halsey probably did not foresee that it would lead to Locklear's demise.
As the battle at Eridanus secundus began, Locklear was ordered to collect supplies from the UNSC Gettysburg. While making his rounds, he decided to destroy the crystal with some explosives he had collected. He covered the artifact with C-7 Foaming Explosive. His judgement was obviously impaired by his bleak situation, and he was very distraught with Polaski's death. Locklear took shelter behind a robotic dolly, but his cover was insufficient. When he detonated the explosive, the artifact was broken into pieces and a brilliant explosion was produced. When the Crystal shattered some of the parts "squeezed" into Slipspace. The humans on board the Gettysburg recovered some shards and chunks of the crystal, while the Covenant only managed to gather a few smaller pieces.
Although Corporal Locklear technically committed suicide, it was most likely unintentional. He was obviously very upset at the death of Sheila Polaski, a Naval pilot to whom he was attracted to, but he also said just before the accident that he "wasn't going to die." It is possible that he was drunk, although the book does not specify whether he drank any of the alcohol or not. Locklear had no idea of the radiation levels the crystal produced, and believed that taking shelter behind a robotic dolly would protect him from the explosion.
It is possible that by completely encasing a radioactive material in explosive, that it would compress in on itself, achieving critical mass and produce a miniaturized nuclear explosion. However unlikely this scenario, an implosion-type first nuclear weapon was the first ever detonated during the Trinity test. This is also supported by the fact that "The brilliant flash of sapphire light was the last thing he ever saw." If Locklear actually did manage to create a small nuclear explosion, then he would have been killed instantly, either by a massive dose of radiation, or he may have simply been vaporized by the explosion that followed. However, the robotic dolly he was hiding behind was still loaded with explosives and ammunition, so the detonation of said ordnance could be the cause of his death.
Locklear, as described by John-117, had numerous traits that allowed him to escape Halo. The most prominent of these traits was luck. In addition, as with most ODST's, he was reckless and had a knack for charging headfirst into a fight with odds heavily stacked against him. The ODSTs' distrust of the Spartans also caused some initial friction between Master Chief and Locklear in the beginning, but later on softened to mutual respect.
- He is one of a handful people to leave Installation 04 alive.
- Locklear is an ODST, but he does not have a full-covering body armor like the Halo 2-3 ODSTs.
- Locklear has a scar lining his jaw.
- He has a dislike of flip music, like most Marines.
- John-117 respected Locklear as an equal, considering him, "As much a warrior as any Spartan."
- Halo: First Strike (First appearance)