the fingerprints found in the murke's home matched robert cowen. >> it goes without saying that i washe department. >> initially on the latent evidence being misread, i tend to believe it was a training issue. >> this was simply a situation where the originalal examiner was in over his head and couldn't handle it. >> armed with the fingerprint evidence and the ballistic test results, robert cowen was arrested and charged with two counts of first degree murder. >> i took him to the office and showed him where his fingerprints were shown in that house and asked him to explain that. he just shook his head and kept his mouth shut and stayed silent and said he couldn't explain it. >> gerald cowen was also arrested for the murders but he was later released because there was no forensic evidence linking him to the crime scene. he was later convicted of manslaughter for killing his father-in-law. he served only two years in prison for that crime before he was released on parole. >> prosecutors believe robert cowen was one of the men seen near the murke's home by the neighbor. based on the for

he had a long record of robberies and use of narcotics. >> robert cowen also had a partner in crime -his brother, gerald. >> the brothers were involved in criminal activity. a lot of small-time stuff, public drunk, a lot of narcotics usage, some assaults. >> forensic scientists tested cliff's gun to see if it was the one used in his murder. the gun of test-fired into a tub of water. as bullets go through the barrel, the lens and grooves which make the bullet spin leave marks on the outside of the bullet. >> they were designed with a certain direction of twist, a certain number of land and grooves, a certain measurement for those land and grooves. so those are intentionally put in by the manufacturer. >> surprisingly when the bullets from cliff's gun were compared to the bullets from cliff's autopsy, they did not match. investigators checked all of the local pawn shops and discovered that the cowen brothers had pawned some of alma merck's jewelry. with a search percent, police found several other items belonging to the mercks in the cowens' possession. >> he had a wallet. he had two so