In 1799, Congress passed the Logan Act. Written in response to the actions of one George Logan, a private citizen who traveled to Paris to head off a potential war between the United States and France. In the 205 years since, no one has ever been convicted of violating it, but it remains on the books.
In the year 1971, John Kerry went to Paris (I'm sensing a theme here) to meet with representatives of the North Vietnam government. While there, Kerry helped to negotiate what became known as "The People's Peace Treaty." Under the terms of that treaty, the United States would agree to an immediate cease-fire pull all forces out of Vietnam. Once that was complete, North Vietnam would then "enter discussions to secure the release of all American prisoners, including pilots captured while bombing North Vietnam." In brief, we'd give them everything, then they'd talk about giving us back our prisoners.
It is important to note that in 1971, Kerry wasn't technically even a private citizen. He was still Lieutenant John F. Kerry, United States Navy (Reserve), and under no circumstances permitted to negotiate on behalf of the United States.
In 1972, while campaigning for a seat in the United States House of Representative (that he eventually lost), he happened to place his office in the same building as one of his primary rivals, Anthony DiFruscia. Just before the primary, the police were summoned to the building. In the basement they found Kerry's brother Cameron and campaign field director Thomas Vallely and arrested them. DeFruscia said they were planning on either cutting or tapping his phone lines; Kerry and Vallely said they had received a tip that DiFruscia was planning on doing the same and they were merely checking their own lines. Kerry won the primary, but lost the general election. About a year after the incident, charges were dropped against Cameron Kerry and Vallely.
In 1984, John Kerry was elected to the Senate from Massachusetts. Barely three months into his first term, Kerry joined Senator Tom Harkin in a trip to Nicaragua, then in the grip of a civil war between the Sandanistas (backed by Cuba and the USSR) and the Contras (backed by the Reagan administration). The Senators met with representatives of both sides, and before they left Sandanista leader (and president of Nicaragua) Daniel Ortega offered the Senators a cease-fire with the Contras in exchange for the US dropping it' support of the Contras. The Reagan administration blasted the Senators's efforts, again citing the Logan Act, but no charges were filed.
According to the US Code, Title II, Chapter 3, Section 39, "The Secretary of the Senate and the Chief Administrative Officer of the House of Representatives (upon certification by the Clerk of the House of Representatives), respectively, shall deduct from the monthly payments (or other periodic payments authorized by law) of each Member or Delegate the amount of his salary for each day that he has been absent from the Senate or House, respectively, unless such Member or Delegate assigns as the reason for such absence the sickness of himself or of some member of his family."
In the current Congress, there have been a total of 617 roll call votes to date - 458 in the first session, 159 in the second (which is still going on). Kerry has attended 159 of the first session votes, 17 in the second - an attendance record of 36% in the first, 10.7% in the second. His combined average for both sessions is 29.5% (all percentages rounded to one decimal place). Kerry has not had his pay docked, nor has he heeded the calls of Massachusetts officials to act as Bob Dole did in 1996 and resign his seat, allowing the state to have the benefit of two full-time Senators, as all the other states enjoy. (Insert gratuitous joke about Ted Kennedy being big enough figuratively and calorically to equal two Senators here).
While not technically fitting into the "crimes" theme I'm pursuing here, Wikipedia also has a table showing Kerry's legislative record over the last ten years. Since 1995, Kerry has sponsored a grand total of 28 bills in the Senate, of which a single one was adopted.
A while ago I challenged people to come up with three achievements of John Kerry's from the last 20 years. The two main respondents cut and pasted this long laundry list of awards Kerry has won (including one named after a former Congressman who was censured after admitting an affair with a 17-year-old Congressional page, while said congressman was more than twice that age), with a single actual piece of legislation mentioned (which was actually the work of Senators Bob Dole and Paul Simon). Politicians of any standing collect these awards like my shoulders collect dandruff; they're part of the "quid pro quo" they get for showing up and speaking to groups.
(After I ripped that list to shreds, the second one came back with a second response. I'll spare you the details; all he did was cut and paste it from here, but neglected to cite his sources. Go look up "plagiarism," Dave. Does Peter Daou of the Kerry campaign know you're using his work without giving him credit?)
My initial challenge was to cite Kerry's achievements from the last 20 years. In answering it, I gave myself the leeway of going back 33 years, and I came up with the above.
(Note: After Dave's failure to give credit, I now feel paranoid about citing my sources. All were found thanks to Google, God's gift to the amateur analysts.)