(Newser) – "There are some unanswered questions to this case," but, according to Santa Clara County Deputy District Attorney Matt Braker, more chilling details are emerging. The case in question is the murder of San Jose, Calif., couple Golam Rabbi, 59, and Shamima Rabbi, 57, whose deaths made national headlines in part because on the hardwood floor near the bodies read the message, "Sorry, my first kill was clumsy." On Wednesday, days after their bodies were found, the couple's young sons were arrested. Now, homicide detectives have shared their findings with prosecutors: Police say Hasib Bin Golamrabbi, 22, shot his father in excess of 12 times in the garage; his mother was shot in the head, ostensibly after walking in on the scene. Motive remains unclear.

Police believe the Rabbis were killed Saturday, April 23, and that the brothers—after allegedly ensuring blood wasn't flowing into the driveway where the neighbors could see it—then went to the Kraken Con anime convention, reports the San Jose Mercury News. Police say the blood detail came from Omar Golamrabbi, 17, who told them his older brother asked him to verify "that blood was not seeping out from inside the garage," reports the Los Angeles Times via court documents. The bodies were found last Sunday. The Mercury News reports part of the reason why both brothers were arrested is because the messages near the bodies were written into two different kinds of handwriting that police say they then linked to the brothers, who have pleaded not guilty. (Read more murder stories.)

