The Franklin, Mass., apartment was searched June 26 by Massachusetts State Police. They found out about the secret apartment from Carlos Ortiz, an acquaintance of Hernandez.
"Hernandez has a second place that not many people know about," Ortiz said. He also told police that he and Hernandez stopped at the apartment the night after Lloyd's death.
There, authorities found ammunition from the same caliber gun used in Lloyd's murder and a white hooded sweatshirt and a baseball cap that match those Hernandez was wearing the night of the murder, as seen on surveillance video.
Hernandez is charged with the first-degree murder of Odin Lloyd, a 27-year-old semi-professional football player, and five counts of gun possession. He has pleaded not guilty and is being held until his trial date. Hernandez was denied bail.
Lloyd's body was found in an industrial park near Hernandez's $1.7 million mansion in North Attleborough, Mass. His body was not discovered until the next day when a jogger spotted him.
Hernandez's mansion and the area around it have been searched several times since Lloyd's body was found.
Hernandez reportedly destroyed his cell phone and smashed his security system during the investigation, and surveillance tapes from his home have a gap after one of the men with Hernandez is seen turning off the camera.
As the case gains publicity, Hernandez has come under investigation for other violent crimes. A former friend is suing him for losing an eye after Hernandez allegedly shot him in the face in February. A lawsuit in the case says that Hernandez "possessed a gun he was not legally licensed to have."
Police are also investigating Hernandez's ties to a 2012 double-murder case in Boston. In that case, two men were shot and killed while waiting at a stoplight. A third passenger in the back seat survived.
Police say that if Lloyd knew about the double-murder, it could have served as a motive for Hernandez to kill him.
A series of grim texts from Lloyd to his sister were sent minutes before his murder to make sure she knew whom he was with.
McPhee, Cokas 'working on their marriage' after affair
LGBT community has 'bullied the American people': Bachmann