Those 11 calls SA made around 9:30 a.m. - to reach an accomplice or to contact the drug dealer for later in the day?
6:30 a.m. to 9:38 (when the phone pings at his mom's) - unaccounted for which has to include the drive to his mother's. They should be able to narrow down a search area.
Probably left the phone at his mother's - returned to use BD's phone to send text message WRUD? - establishing an alibi - enough time to return to get his mom's to get the phone, return to BD's house around the time he "usually" gets there.
6:30 a.m. to 9:38 (when the phone pings at his mom's) - unaccounted for which has to include the drive to his mother's. They should be able to narrow down a search area.
Probably left the phone at his mother's - returned to use BD's phone to send text message WRUD? - establishing an alibi - enough time to return to get his mom's to get the phone, return to BD's house around the time he "usually" gets there.