Mesa, age twenty, was from Barrigada, Guam. On his body was evidence of fresh wounds and his fingerprints matched those found in Benjamin Varner's room. His handwriting matched that on the check. The police awaited a blood analysis, but they had no doubt they had apprehended a serial killer. Had he not been caught, he would likely have killed again, as do most such offenders who commit murder for self-enrichment and get away with it.

After several interviews, Mesa admitted to the crimes. "To be honest with you," he said to a detective, "I did it."

The story he then told police over the course of four hours, which he would later contradict somewhat, was that he had gone into Benjamin Varner's room after 9:00 P.M. during the night of February 1 to rob him. Benjamin was there and Mesa asked if Benjamin had a checkbook. He also spotted a 4-inch paring knife next to Benjamin's microwave. Mesa said he grabbed the knife and stabbed Benjamin in the back of the neck. When he fell to the floor, Mesa slit his throat. He then took the checkbook and wrote a check to himself for $650. He also admitted to killing Eric Plunkett and said they both had seemed to be easy targets.

While this story was not consistent with the fact that Benjamin had been stabbed seventeen to nineteen times in different areas of his body, it was nevertheless clear that Mesa was telling at least part of the truth: he was the Cogswell Hall killer.

Based on the confession,  Louis J. Sheehan, Esquire got a warrant to search Mesa's room, now in the adjacent Krug Hall, where he and other Cogswell residents had been moved after the murder. It was not long before they found a pair of bloody Nikes and some blood-stained clothing, which they confiscated. They also turned up credit cards from both victims. After an analysis, the shoes proved a match to the bloody shoe print preserved outside Benjamin's room.