general Quan Xiancheng (), the grandson of the former Goguryeo regent Yeon Gaesomun and, when Quan refused, falsely accused Quan of treason and had him strangled. In 693, the officials Pei Feigong () and Fan Yunxian () were accused of secretly meeting with the crown prince Li Dan (the former emperor), and when Fan tried to speak on his own behalf, Lai had his tongue cut off, and then had Pei and Fan both executed by being cut in half at the waist. Wu Zetian decreed that officials would not be allowed to meet with Li Dan. When, subsequently, there were secret accusations that Li Dan was plotting to overthrow her, she had Lai investigate Li Dan's associates, whom Lai arrested and tortured. One of them, An Jinzang, proclaimed Li Dan's innocence and cut his own abdomen, causing the organs to fall out. When Wu Zetian heard this, she was touched, and she had the imperial physicians treat An, barely saving his life, and on account of An's assurance that Li Dan was not plotting against her, ordered Lai to end his investigations against Li Dan. Meanwhile, Lai falsely accused the minister of public works, Su Gan (), of having been a co-conspirator of Li Chong's, and had him executed. Either in 693 or 694, Lai was accused by the imperial censor JI Lüzhong () of five crimes, including corruption, and initially, Lai was sentenced to death, but Wu Zetian, believing him to have accomplished much for her, spared his life and reduced him to commoner rank—and soon thereafter reinstated him as secretary general of palace affairs (殿中丞, Dianzhong Cheng). Lai was, however, thereafter again accused of corruption, and he was demoted to be a military officer at Tong Prefecture (同州, roughly modern Weinan, Shaanxi), interrupting his career as a secret police official. Second stint as secret police official In 696, Lai Junchen was recalled to then-capital Luoyang to serve as the sheriff of Hegong County (), one of the two counties making up Luoyang. In late 696, the sheriff of Mingtang County (明堂, one of the counties making up Chang'an), Ji Xu, heard about a treasonous plot by the officials Liu Sili (), Qilian Yao (), and Wang Ju () -- as the conspirators believed that Qilian was fated to be emperor one day. Ji relayed the plot to Lai, and had Lai submit a secret report of it.