so, derek, he was a good guy, good cop, good friend. reporter: derek was just 32 years old, leaving behind his wife, his 6-year-old sorngs and his family at draper p.d. you know everybody talks about a cop s cop and the best cop you can have and how he treated and served the community. derek was one of those guys. reporter: for jaclyn moore, the loss was two-fold. he was starting to get some free time to come help me with the case and tell me more about what he did when he was on the case. and then he was killed. i didn t have anyone else to ask. reporter: you d lost your friend. your old competitive friend. i lost my friend, and i lost any information that i needed on that case. there was no one else. reporter: because he was kind of the institutional memory of this thing, wasn t he? yes. reporter: jaclyn had only herself to rely on now. in the balance, justice for
annie kasprzak had been brutally murdered and dumped into the jordan river. we kept asking, are you sure it wasn t an accident? the idea that somebody else could do that to her was just even now, it s hard to imagine that that s even possible. reporter: and now draper police were working hard to catch her killer. we re trying to actively locate suspects in this case, any witnesses, so we can actually bring this case to a conclusion for the parents. reporter: and within a week of annie s murder, they found that witness. her name was joanna, and she had been picked up on a fraud charge
by neighboring west jordan p.d. during her interview, she started telling detectives about a young girl she had seen a week prior. the cops thought some of what she said sounded eerily similar to annie s case. so they called draper p.d., and detective derek johnson and his colleague came over to hear what joanna had to say. tell me what you know about this girl. it was the second time i ve seen her over there. reporter: there at the home where a man named daniel ferry used to live. danny ferry is a guy known to law enforcement? yes. reporter: as maybe a drug dealer? drug dealer. he was a member of a gang called vario loco town. and law enforcement has dealt with danny quite a few times, yeah. reporter: ferry had a long rap sheet. in fact, derek had served a search warrant on his home a year earlier. and now here was joanna telling derek that she saw a girl who sounded a lot like annie at daniel ferry s home on the night annie was killed. joanna also said the girl showed u
by neighboring west jordan pd. during her interview, she started telling detectives about a young girl she had seen a week prior. the cops thought some of what she said sounded eerily similar to annie s case. so they called draper pd, and detective derek johnson and his colleague came over to hear what joanna had to say. tell me what you know about this girl. it was the second time i ve seen her over there. reporter: there at the home where a man named daniel ferry used to live. danny ferry is a guy known to law enforcement? yes. reporter: as maybe a drug dealer? drug dealer. he was a member of a gang called vario loco town. and law enforcement has dealt with danny quite a few times, yeah. reporter: ferry had a long rap sheet. in fact, derek had served a search warrant on his home a year earlier. and now here was joanna telling derek that she saw a girl who sounded a lot like annie at daniel ferry s home on the night annie was killed.
good cop. good friend. reporter: derek was just 32 years old, leaving behind his wife and his 6-year-old son and his family at draper pd. you know everybody talks about a cop s cop and the best cop you can have and how he treated and served the community. derek was one of those guys. reporter: for jaclyn moore, the loss was two-fold. he was starting to get some free time to come help me with the case and tell me more about what he did when he was on the case. and then he was killed. i didn t have anyone else to ask. reporter: you d lost your friend. your old competitive friend. i lost my friend, and i lost any information that i needed on that case. there was no one else. reporter: because he was kind of the institutional memory of this thing, wasn t he? yes. reporter: jaclyn had only herself to rely on now. in the balance, justice for