Did not intend to intimate involvement in the assassination, have found no credible sources or other information to support the the idea that Nixon had direct involvement. Just provide information of the fact of.

Conflicting stories about Nixon in Dallas that day. See Prouty link below.

Concur its a little hinky that three future presidents (that's including Johnson even though it was not so hinky he was there being from Texas) are in proximity to Kennedy's assassination. See info below:

In 1963 the Nixon family traveled to Europe, where Nixon gave press conferences and met with leaders of the countries he visited.[110] The family moved to New York City, where Nixon became a senior partner in the leading law firm Nixon, Mudge, Rose, Guthrie & Alexander.**[100] When announcing his California campaign, Nixon had pledged not to run for president in 1964; even if he had not, he believed it would be difficult to defeat Kennedy, or after his assassination, Kennedy's successor, Lyndon Johnson.[111]

https://en.wikipedia.org/wiki/Richard_Nixon

June August 1963 Nixon and family visit Europe... to include East Germany.

Quite the intinerary:

https://issuu.com/richardnixonfoundation/docs/europe_summer63_itinerary

21 / 22 November 1963 Dallas TX

http://www.prouty.org/nixon.html

24 November Washington D.C.

https://youtu.be/XyoyNF2MbIY

At least Nixon kinda knew where he was...

Bush 41 reportedly couldn't even recall:

https://youtu.be/Je_7CNWa-Ek