that lead nowhere. so chavez and his team focused on the crime scene. there was no murder weapon. they did find two spent .45 caliber casings. reporter: and near an observation deck just thirty feet away from where mollie and kristene were discovered, police found an empty monster energy drink can and five cigarette butts. and the girls didn t smoke? the girls did not smoke. reporter: chavez sent all that for dna testing. as for the duct tape used to cover the girls eyes, chavez thought maybe that was itself a clue. sometimes that can suggest somebody who knows the victim. didn t wanna see them. yes, uh-huh. far as you know, either of them have any enemies? no. that s what was so confusing. everyone loved them, you know. reporter: and that s probably why they were all so discreet when it came to kristene and mollie. now, as a murder investigation
and more things that are lining up. for example? the use of numbers. reporter: remember, kristene said the shooter referred to her and mollie as girl one and girl two. did he use numbers in that other crime? yes, they referred to each other by number in that particular crime. reporter: the similarities between the two crimes didn t end there. in the nevada home invasion was the victim found? yes, they were. definitely jumped to the top. reporter: by that time, dylan stallman had already returned to nevada to begin serving his three-year sentence. so chavez hopped a plane to las vegas, hoping to hear what mr. stallman might reveal about his brief stay in texas. stallman admitted he was in the park the night of the shootings but he denied being anywhere near the area where the girls were found. he said he was never on the deck. well, we ve got dna on the cigarette butts that prove otherwise. why lie about that unless
are lining up with what we re looking at. for example? the use of numbers. reporter: remember, kristene had said the shooter referred to her and mollie as girl one and girl two. he used numbers in that other crime? yes. they referred to each other by number in that particular crime. reporter: the similarities between the two crimes didn t end there. in the nevada home invasion, were the victims bound? yes, they were. he s gotta be number one on the list at this point. he he definitely jumped to the to the top. reporter: by that time, dylan spellman had already returned to nevada to begin serving his three-year sentence. so chavez hopped a plane to las vegas, hoping to hear what mr. splmanig reveal about his brief stay in texas. spellman admitted he was in the park the night of the shootings. but he denied being anywhere near the area where the girls were found. he said he was never on the deck. well, we ve got dna on the cigarette butts that prove othe
reporter: tips were coming in. someone said they saw a white car speeding from the park the night of the shootings. that lead nowhere. so chavez and his team focused on the crime scene. there was no murder weapon. they did find two spent .45 caliber casings. reporter: and near an observation deck just thirty feet away from where mollie and kristene were discovered, police found an empty monster energy drink can and five cigarette butts. and the girls didn t smoke? the girls did not smoke. reporter: chavez sent all that for dna testing. as for the duct tape used to cover the girls eyes, chavez thought maybe that was itself a clue. sometimes that can suggest somebody who knows the victim. didn t wanna see them. yes, uh-huh. far as you know, either of them have any enemies? no. that s what was so confusing. everyone loved them, you know. reporter: and that s probably why they were all so discreet
dylan spellman was in the corpus christi area, awaiting sentencing for the nevada armed robbery. he had been sent here to to stay with a friend. reporter: what intrigued chavez were some unusual similarities between the nevada crime and the shootings in texas. as we started going through that case file, we started seeing more and more things that are lining up with what we re looking at. for example? the use of numbers. reporter: remember, kristene had said the shooter referred to her and mollie as girl one and girl two. he used numbers in that other crime? yes. they referred to each other by number in that particular crime. reporter: the similarities between the two crimes didn t end there. in the nevada home invasion, were the victims bound? yes, they were. he s gotta be number one on the list at this point. he he definitely jumped to the to the top. reporter: by that time, dylan spellman had already returned to nevada to begin serving his thre