BOISE - E-mail scammers and spammers often offer generous rewards to those naive enough to send cash in exchange for big lottery winnings.

Now con artists are trying scarier tactics: death threats and extortion, the Ada County Sheriff's Department said.

Authorities say messages that claim to come from a hired killer are showing up in email boxes across the Northwest, including here in Ada County.

The sender says he is a hit man hired to kill the recipient and orders that person to send thousands of dollars to stop his own murder. The message warns recipients not to contact authorities.

Ada County Sheriff's detectives are investigating a death threat email sent to an Ada County man. They do not believe the email is aimed at a specific person but is a form letter sent to many recipients trying to scam money from them. Detectives urge you not to respond to the emails.

Because nearly all of the emails originate in foreign countries, law enforcement officers do not have the ability to prosecute the sender.

Here is a copy of an email that's come to the Treasure Valley:

Subject: Hired To Kill You....
Dear Friend,

"It is important we come to a conclusion now or never because, I have been hired to kill you, this is the simple fact and I have been paid well for this job to be sincere with you, I have your full data’s, from your name, to your address, to your phone numbers including this email address. I watch you everyday since the past two weeks and I know where you go and when you come back and everything you do. Do not dare me, I am a born killer, which is what I do to survive, I was born and brought up in Mexico."

"Never the less, I do not want to kill you, reasons best known to me, only if you will comply with my ransom and I will let you go and even send you the pictures of the person in charge (Who Paid me to kill you) including a very important video tape that you might need."

"NOTE: No Police. Ignore this message if you wish to die, I give you 5 days to comply or I will come for you. I am presently on another assignment. You have your choice."