Jose Abad Santos was 56 years old in 1942, a vigorous age, and we meet him far from the capital of Manila "traveling somewhere around Carcar, Cebu, with his son, Jose Jr., Colonel Valeriano of the Philippine Constabulary, and some enlisted men". This incident is extremely suggestive. Rather than wait in Manila to meet and negotiate with the Japanese, the Chief Justice is encountered doing the rounds in uncaptured territory, "unaware that the enemy had landed in the vicinity". Given his military entourage; the fact his capture occurred before Wainright's final surrender in Corregidor, and Cebu's proximity to Mindanao I think probability is that Abad Santos was setting up resistance cells when he was surprised by the Japanese.
The Japanese must have understood this immediately. "For almost 20 days, he was subjected to grueling and mortifying inquisition. The exact nature of the investigation is still shrouded in secrecy." There is evidence that the Japanese were primarily interested in operational intelligence, rather than political cooperation, from Abad Santos. "Previously, however, he had been asked to contact General Roxas somewhere in Mindanao who up to that time had not yet surrendered. In all probability, the Japanese wanted him to induce General Roxas to surrender."
Probably the only thing that kept the Japanese from killing and torturing Abad Santos outright was his possible utility as a collaborationist figurehead. Abad Santos knew it and played the card immediately by identifying himself as the Chief Justice. It kept him alive for three weeks. Why then did the Japanese decide to shoot him on the day after Corregidor surrendered? The only answer I can come up with is that the Japanese had found other high ranking Filipinos willing to serve in their puppet government, who had probably waited until the final denouement before throwing in with Nippon. Once a set of collaborators had been found, Abad Santos's potential political utility was at and. He was simply an operational prisoner and doomed.
Meanwhile, the Democrats continue to show us continuing examples of their treasonous behavior.