K Rajashekar, the accused, had been advised by somebody to commit a human sacrifice for curing his wife's chronic illness, police said.
He abducted an abandoned baby girl, around three months old, from the roadside in Boyaguda area on January 31, said Rachakonda police commissioner Mahesh M Bhagwat.
Around midnight, he beheaded the girl, threw the torso and the knife into the Musi river, and performed 'Kshudra Pooja' (a black magic ritual) with his wife Srilatha (35) at their house in Chilukanagar with the severed head on the altar, Bhagwat said.
Later the head was kept in the south-west corner on the terrace of the house, under "the lunar eclipse light and the (light of) rising sun around 4 am" (as he had been advised), the commissioner said.
A total lunar eclipse had occurred on January 31.
Rajashekar then left for work as usual, but his mother in-law saw the severed head around 11 am and raised alarm. Subsequently, police were informed.
Police analysed call detail records of 122 mobile phones, questioned 45 suspects and examined footage from more than 100 CCTV cameras during the probe, Bhagwat said.
After a forensic lab report revealed that traces of blood found in Rajasekhar's living room and that of the severed head found on the terrace shared the same DNA profile, police confronted him, and he confessed to the crime, the commissioner said.
Srilatha wasn't keeping well for the last four years, and somebody had advised the couple to commit 'sacrifice' ("Nar-bali") of a girl child to rid the woman of "evil spirits", he told police.
Rajashekar decided to look for an abandoned child so that its going missing would not be noticed, the commissioner said.
A case of murder, kidnapping and other relevant offences has been registered against the couple under the IPC.
Bhagwat today also appealed people to come forward to identify the slain girl.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)