Cadell Jeansen Raja, who was absconding since yesterday, was taken into custody from the Thampanoor railway station here soon after alighting from a train, police said.
The 30-year-old Raja, an MBBS dropout, pursued engineering in Australia, but returned after failing to complete the course.
Later, he took to animation and was said to have developed a games search engine for an Australian firm, police said.
Police had issued a look out notice for him yesterday.
The murder came which came to light on Sunday, had sent shock waves as it took place in the city's posh Nathencode locality, close to Cliff House, official residence of Chief Minister, Pinarayi Vijayan and some of his cabinet colleagues.
Another body of a close relative, Lalitha, was found in a highly decomposed state cut into pieces and packed in a sack.
The deceased were identified that of Dr Jean Padma, a Cardiologist, her husband Prof Rajathankam, their daughter Caroline, who was pursuing MBBS in China.