Investigators discovered disturbing videos of two missing women inside a Philadelphia house who are now believed to be dead. NBC News’ Valerie Castro has the latest on what police found and what brought them to that house in the first place.

Ten government lab workers have mysteriously died or disappeared in the last three years and conspiracy theories have swirled about whether the cases are connected. One of the missing, Melissa Casias, was found dead in May – nearly one year after she went missing. Last week, a newly-released autopsy revealed the cause of death was a gunshot wound. Casias disappeared while working at Los Alamos National Laboratory in New Mexico, where her husband, Mark, was also employed. CBS News' Anna Schecter