Internal Forensic Report

The audio recording acquired by the police surveillance of the dental office has been analysed. Using Fourier filtering methods, the forensic specialists have successfully isolated the voice of James Carver. In this recording, he says,

"Robert? He's dead. I killed him." (audio)

Based on this analysis, we believe that this recording can be used to justify the arrest of James Carver.

Internal Police Report: Surveillance of James Carver

Mr. Carver's phone address book shows an appointment labelled "Dentist: Routine Cleaning" scheduled for July 11. It also showed a similar appointment for June 27. However, correspondence with Mr. Carver's dental insurer revealed that he is not covered for such frequent dental procedures. Hence, it is our opinion that these appointments are covers for meetings.

We have attained a warrant to install covert listening devices in the dental clinic to record audio during Mr. Carver's meeting on July 11. Our hope is that their conversation will reveal information about the murder of Robert Durst.

Forensic Report: Unlock Code for Mr. Carver's Phone

The forensic specialists have analysed the touch-screen log data of Mr. Carver's phone, and established a candidate unlock pattern, as shown below.

Internal Police Report: Durst Murder Case

After forensic investigation of the body of Robert Durst, analysts conclude that he died between 9:15am and 9:30am on June 12. Based on the alibis of three suspects, James Carver is now the main suspect.

The district attorney has indicated that the case against Mr. Carver is not strong enough for a conviction. More evidence is needed.

BREAKING NEWS: Dead Body Found

June 13 - Police discovered a dead body as they moved in to arrest a suspect in an illegal trading ring. The identity of the deceased has not been released by police, but insider sources say it is likely Robert Durst, the suspect implicated as the leader of the trading network. Forensic experts are now in the process of determining the time of death to eliminate potential suspects.

Internal Police Report: Analysis of Trading Network

Background: The money skimmed from First National Bank was being used to purchase contraband goods.  Dennis Reader, charged with embezzling money from the bank, has been cooperating with police, supplying them with information about the trading network. Mr. Reader has been released on bail.

Analysis: Forensic analysis has revealed that Robert Durst (labelled "H" in the network) is the dominant trading member (as indicated by his eigen score). However, two other members of the trading network are also influential: Samantha Brundi, and James Carver (labelled "G" and "J", respectively).

Recommendation: In total, four perpetrators have been identified:

• Dennis Reader
• Robert Durst
• Samantha Brundi
• James Carver

We recommend that these suspects be investigated further for their involvement in the trading of illegal goods, and the embezzling of funds.

Forensic Financial Analysis of First National Bank

The forensic team has completed its analysis of the financial computing software for First National Bank. Our findings indicate that "siphoning" (or "skimming") was occurring.

The software takes a list of 10,000 credit transactions and 10,000 debit transactions and calculates the net balance

However, the calculations were carried out using the IEEE single-precision floating-point number system, which maintains approximately 8 significant digits.

The net was computed by the software using 3 different methods.

Method A simply calculates the sum of the credits, and subtracts from it the sum of the debits.

Method B calculates the sum of the credits, and then subtracts the debits, one at a time, from smallest in size to the largest.

Method C sorts both the credits and debits, from smallest in size to largest, and incorporates them into the net in credit/debit pairs, starting with the smallest.

Finally, the program returns the minimum of the 3 values.

Mathematically, these three methods are equivalent. However, they can result in drastic differences when round-off error is present.

Our analysis indicates that Method C is the most accurate because it results in much smaller intermediate values. Using Method A or B, intermediate values can be larger in size than $100,000,000, which means the round-off error (for IEEE single-precision) would be around the "tens" digit. These round-off errors can accumulate.

Since the function returns the minimum of the three methods, we conclude that the author of the code intended the software to under-report the net value of the calculation, and "skim" the unreported dollars into their own bank account.