The killer allegedly targeted slum-dwellers and pavement dwellers, killing them with broken bottles of beer and dumping their bodies on the shores of the Arabian Sea.
The prosecution had sought a death sentence against the accused but the court declined the plea on the grounds that this not 'the rarest of rare cases' and sentenced him to life imprisonment.
Shortly after the verdict of the lower court, Kunjuraman challenged it in the Bombay High Court which found him not guilty Thursday.
Kunjuraman said that contrary to allegations that the accused was insane, Kantrole is very much in control of his senses and had been wrongly picked up in the case.
Kantrole lived outside a Muslim mausoleum at New Marine Lines in south Mumbai when the murders took place.