>> yeah. >> did jessyka trust john?>> no. >> i know she was planning on filing for sole custody of dominick, because she was just tired of it and half the time when it was john's time to take him, he refused. >> they had these fights over dominick, over custody, over money. jessyka was routinely upset with him. >> reporter: john seemed to be trying to minimize those issues. >> do you have issues where you're at each other's throats or anything like that? >> no, no. the biggest thing that we might fight about is she's like, "you have a pair of shorts that i bought him two weeks ago and i haven't got to see them since i sent him to your house. you need to find them." >> okay. >> reporter: after a few hours of questioning, they let john go with a warning. he was suspect number one. and they kept an eye on him as they investigated other men who'd crossed paths with jessyka. >> we were interested in any male party she had recently been introduced to, anybody at all that could have been showing interest in her, communicating

. >> you could see marks on jessyka's neck. >> they said, "we're going to rule this as a homicide." > entry, no tool marks. >> there was blood on the couch. >> who could have done this? >> they say that usually someone close. >> an ve