The medical student accused of poisoning his pet for compensation had showed signs of mental problems during his last year at Mahidol University's Faculty of Medicine at Siriraj Hospital, an alumnus revealed on condition of anonymity yesterday.
"He seemed normal until his sixth year at the university," the source said.
A medical lecturer noticed that the student had problems controlling his emotions and the faculty resolved to suspend him from his studies to allow him to focus on treatment for his condition, the source said.
"Classmates in the same year have already graduated," the alumnus said. "I am not sure if he is still being treated."
The medical school was expected to summon the student and his parents today. The mother of the student said yesterday she did not know what her son had done because he had moved to Bangkok for his studies seven years ago.
"I really can't comment," said the mother, who lives in Nakhon Ratchasima.
On Saturday, Nattanan Jeerawiwitporn - who owns a transport firm - filed a complaint with the Sutthisan Police Station in Bangkok over alleged fraud by the medical student on the grounds that he had demanded compensation for the death of a Pomeranian dog that had arrived safely at a clinic.
Her firm is based in Bangkok but the clinic is in Nakhon Ratchasima.
"The insurance he took out offered coverage in the event that the dog died during transportation only," Nantanan said.
She said she would find out later whether the same student had contacted a transport firm run by her younger brother seeking to transport 10 insured rabbits on July 29.
"But my younger brother refused," Nattanan said.
Suttisarn Police Station's deputy superintendent Pol Lt-Colonel Seubpong Karuna said there was incriminating evidence about the fraud charge, given that the accused apparently faked a certificate stating his pet dog's price.
Pol Major Mongkhon Kupatisirirat, an inspector at the Pho Klang Police Station, said he was investigating alleged animal cruelty committed by the medical student.
Twelve pills were found in the deceased dog's stomach and another in a wastepaper basket, all of which will be submitted for lab tests today.
"We have already questioned three witnesses," Mongkhon said. He added that he would summon the accused student later this week.