Fullerton wanted justice. The white man story does not seem to have been followed up. After testing the flashlight found at the scene, Orange County authorities found a perfect set of fingerprints. Because these prints did not match those of the Mexican suspects, the men were cleared of suspicion. Orange County offered large rewards for the killer; fearing violence should justice be delayed.
Luckily for them, a former Orange County resident now residing in Topock, Arizona, had been following the case in Los Angeles papers. Fred Lewis, a telegraph operator, had lived locally in Bolsa. Thus, he "was deeply interested in the case because of having lived there at one time. This caused him to pay particular attention to the negro." Seeing a suspicious-looking Negro buying a ticket to Albuquerque that, to him, matched the description in the papers, Lewis stalled the man while telegraphing to Needles for some officers. It would take five officers to subdue the Negro. Apparently, Constable West of Needles was not legally able to bring in the suspect, identified as Mose Gibson, without a warrant. But that did not matter to Constable West. As the Santa Ana Register relayed the encounter:
"As West arrested Gibson, the negro is said to have remarked: 'Huh, white man, you can't arrest me and take me back to California. You ain't got no warrant.'
'No, you black fiend,' the constable is said to have replied. 'I haven't got a warrant, but I have got a gun, and I'm going to take you back to California.'"
West secured Gibson, wrangled out a confession, and held him while awaiting the arrival of Sheriff C.E. Jackson of Orange County.
Gibson was scared and feared a lynching. The Santa Ana Register went on to describe that "When the Santa Ana party arrived Gibson was moaning and praying and singing religious hymns. He was frightened by the arrival of the Santa Ana party, evidently believing it to be a lynching party." Gibson was so frightened that he refused to talk to anyone present until speaking to a local Catholic priest, who reassured him that the Santa Ana men were not there to kill him but were there to protect him from a lynching.
With Gibson captured, the Santa Ana men needed to help him escape. Orange County authorities wanted to avoid a lynching, but the people of Fullerton had already planned to intercept the prisoner and seek justice for themselves. According to the Los Angeles Herald, "Oil workers in the Fullerton field were reported to have held a mass meeting and to have voted in favor of burning the murderer at the stake. Three hundred men attended the meeting. Only 12 voted to let the law take its course, according to dispatches." To foil any attempt at a lynching, Sheriff Jackson and his men planned a moonlight escape, driving side roads in a circuitous route from Arizona back to southern California. The Los Angeles Times described how after a short breakfast, the officers "left Barstow and took the Victorville Road, making a wide swing around the territory where automobiles from Orange county, carrying loads of grim men with purposes of their won awaited them. Gibson showed relief when he was behind bars. Not until things quieted down, did his moody eyes stop shifting in every direction, and his long, gorilla-like jaw come to rest."
Upon arrival, justice was swift and unforgiving. As the Los Angeles Herald put it, "Foiling any attempt at lynching, stern justice sped on its course today and Mose Gibson, confessed slayer of Roy G. Trapp, Fullerton rancher, was sentenced to be legally hanged on Sept. 24. Tonight he will be on his way to San Quentin. All local records in dealing with a murderer were broken in the case of the negro, but two hours being required for all the formalities." Gibson arrived in LA around 3 am, reached Santa Ana to undergo his preliminary hearing by 5 am, was declared guilty by 7 am, and was on his way to San Quentin by noon. September 24 was chosen, as it was the earliest date of execution allowed by law at the time. Under the law, sixty days had to pass before a man could die by hanging for his crime.
With the doling out of swift justice, peace could reign in Orange County. Would-be lynchers could rest easy knowing that not only had a suspect been captured, but by the end of the day his death sentence was secured. Over the course of his capture and transfer, Gibson made several - often conflicting - confessions. But the little community south of Los Angeles could avoid a lynching and a riot. Sheriff Jackson pledged to the people:
"We are all apt to get hot at first, but we must keep in mind that it would be unfortunate if hot-headed action should leave a blot upon the citizenship of Orange County," said Sheriff Jackson. "The Law can give this man all he deserves, and it will not tarry, either. We have a complete case against him and with his confession justice will be handed out with speed and certainty. I certainly hope that every good citizen will do all in his power to uphold the law."
