Updated below. One nagging detail in the scandal involving David Petraeus, retired general and now former CIA director, is why the FBI and not local police investigated the allegedly threatening e-mail messages said to have started it all.

Anyone who has looked at the Fridley Police Department's weekly incident reports knows that they handle a wide range of complaints about e-mail, text and voicemail messages.

'Why This One Case?'
An article posted Monday by the New York Times tries to answer the question:

Is a string of angry e-mails really enough, in an age of boisterous online exchanges, to persuade the F.B.I. to open a cyberstalking investigation? ... Some commentators have questioned whether the bureau would ordinarily investigate a citizen complaint about unwanted e-mails, suggesting that there must have been a hidden motive, possibly political, to take action.... Orin S. Kerr, a George Washington University law professor who specializes in computer crime issues, said it was “surprising that they would devote the resources” to investigating who was behind a half-dozen harassing e-mails. “The F.B.I. gets a lot of tips, and investigating any one case requires an agent or a few agents to spend a lot of time,” he said. “They can’t do this for every case, and the issue is, why this one case?”

The Times article offers several reasons for federal involvement:

• The report seemed to be "a legitimate complaint about e-mail harassment."
• Petraeus biographer Paula Broadwell, "the author of the e-mails ... seemed to have an insider’s knowledge of the C.I.A. director’s activities."
• The complainant, Jill Kelley, contacted "a rank-and-file agent she knew from a previous encounter with the F.B.I. office." (That agent "had previously pursued a friendship with Ms. Kelley and had earlier sent her shirtless photographs of himself," the Times said, and the FBI is now probing his actions as well.)

Update (9 a.m. Tuesday): The Fridley Police Department and the FBI responded by email. Kyle Loven, spokesperson at the FBI's Minneapolis office, said:

There are circumstances when the FBI would become involved with respect to threatening email communications.  If the communications were interstate or international in nature for instance, the FBI would become involved.  Again, it would depend on the circumstances surrounding the communications.

Lt. Mike Monsrud of the Fridley Police Department said:

We would encourage people who receive threatening e-mails to report them to their local police department. I assume the FBI got involved in the Patraeus case because it involved high ranking military personnel and other government employees with federal security clearances that could potentially be compromised. The majority of reports we get are people who receive potential scam e-mails. We report those incidents to MNSCAMS.org which is a division of the Minnesota Attorney General’s Office. One of the most recent scams is that the scammers will e-mail or call you telling you that they are collecting an old debt for a collection agency and if you do not wire them some money immediately they will issue an arrest warrant for your arrest. This is always a scam. That is not how the process works. Never send money to someone you do not know. Most of these scam type e-mails originate out of the United States and we have no jurisdiction in those cases.

Many of these e-mails are very difficult if not impossible to trace due to the level of sophistication on the part of the senders.

Recent Incidents in Fridley
In the last five weeks, Fridley police have responded to at least seven reports of threatening or suspicious text messages, voicemails and e-mails, according to the department:

• Oct. 5, 2012, 10:19 a.m.: A female reported receiving several threatening text messages, possibly from her ex-boyfriend. Investigation to follow.
• Oct. 17, 2012, 10:27 p.m.: Police responded to the location on report of harassment. The caller advised she received a text message that led her to believe her ex-boyfriend was waiting for her at the location. Police searched the area and did not locate the ex-boyfriend.
• Oct. 17, 2012, 12:36 p.m.: Caller said a strange male sent her some text messages. She called the male and told him to stop, but wanted the police to do the same.
• Oct. 18, 2012, 8:11 p.m.: Dispatched a phone call report in regards to harassment. I spoke with the caller, who advised she has received odd voicemails and believes they are from her sister. The caller advised she no longer wants to have contact with her. I spoke with the caller’s sister who denied making any phone calls and advised she will continue not to.
• Oct. 26, 2012, 10:39 p.m.: A complainant reported a female sent her unwanted text messages harassing her about her brother-in-law. The suspect was contacted and informed to stop sending the messages. The suspect said there would be no more contact from her.
• Oct. 31, 2012, 11:13 p.m.: Dispatched to a phone call report in regards to suspicious activity. The caller advised of a suspicious e-mail that he had received stating he won a large amount of money. The caller believed the e-mail could possibly be fraudulent. Police advised the caller to delete all suspicious e-mails and to not give out any personal information.
• Nov. 1, 2012, 6:48 p.m.: Dispatched to a phone call threat report. I spoke to the caller who is running for State House Representative and has received a threat on an election mailing that was placed in her mailbox. Copy to Detectives for further follow up if necessary.

Is it best for local police to handle e-mail threats, or should the FBI investigate them? Did the Petraeus/Broadwell/Kelley case get the right treatment in your opinion? Leave a comment below.