REOPENKENNEDYCASE - 

Most of the little we know about Oswald's account of his own actions on November 22 comes to us second-hand. In explaining why he left the Depository shortly after the assassination, he (apparently) described how he "went outside and stood around for 5 or 10 minutes with foreman BILL SHELLEY, and thereafter went home. He stated that he left work because, in his opinion, based upon remarks of BILL SHELLEY, he did not believe that there was going to be any more work that day due to the confusion in the building" (WR p. 619).

This statement was not rendered until James Bookhout's solo report, filed after Oswald's death, and based upon notes he'd taken during Oswald's initial interrogation. This detail, notably, was omitted from a joint report that Bookhout had filed with James Hosty the day before Oswald's murder.

But "Shelley denied seeing Oswald after 12 noon or at any time after the shooting" (WR p. 182), and the Warren Commission opted to determine that the incident never happened.

Shelley and his trusty sidekick Billy Lovelady had watched the motorcade from the TSBD front landing. And their testimonies give the impression that they remained there upwards of 3 or 4 minutes after the shots, confusing the arrival of Gloria Caverly with that of motorcycle officer Marrion Baker. Years of film analysis have firmly established that Baker, racing along Houston Street, reached the front steps 22-23 seconds after Z-313; Caverly, who'd been down at the Stemmons sign, was nowhere near Baker then. And so their mis-synchronization has, erroneously, been chalked up to S & L's mis-memories of those confusing first few minutes.

Thanks to some superb film work by researcher Gerda Dunckel (Couch film/Lovelady and Shelley?), we now know that S & L left the front steps several seconds before Baker even arrived there.
http://www.jfkassassinationforum.com/index.php/topic,6724.24.html

S & L each testified that they walked down the Elm St. Extension about 100 yards to the 1st railroad track in the west parking lot. Although they had claimed in their brief FBI interviews 3 weeks earlier (WC Exhibit 1381) that they'd stood out there "about 10 minutes" & "approximately 5 minutes", their testimonies clarified that it was "maybe a minute or two" (WCH VI p. 331) & "just a minute, maybe a minute and a half" (VI p. 339). Setting Z-313 at 12:30:00, and gauging from the Couch film, their estimated arrival at the railroad track can be placed at 0:45 seconds; they stayed there until about 1:45- 2:15

This photo from David von Pein's collection illustrates this west area of the TSBD (scroll down to the 3rd photo in "Dealey Plaza Through the Years", then zoom in). Take note of the door with a ramp next to the carport, as well as the fire door built into the corner of the main warehouse.
http://www.Kennedy-photos.blogspot.com

We probably won't ever know what compelled S & L to re-enter the Depository at this juncture, but it is interesting to consider that, during this 1:45- 2:15 timeframe, Truly & Baker had paused to scan the 4th floor, and Adams & Styles were approaching S & L from the rear of the building.

Robin Unger's collection has a photo extending further along the building's northwest side, and shows that the wooden doors built into the Rear Annex had no ramp.
http://www.jfkassassinationgallery.com/displayimage.php?album=31&pos=93

Lovelady testified (VI p. 339) that "we went back into the west entrance on the back dock had that low ramp" and went through (p. 340) "that double door that we in the morning when we get there we raised. There's a fire door and they have two wooden doors between it."

The 1st-floor diagram- which omits the West Annex (!!aha??)- shows that Lovelady is talking, somewhat muddledly, about entering the overhead doors that connected the West Annex with the rear of the main warehouse.
http://www.maryferrell.org/mffweb/archive/viewer/showDoc.do?docid=10896
at page 7.

We now see, with the benefit of the new film evidence, that S & L were capable of returning, at a comfortable pace, to the front entrance by 12:33:30. But they weren't asked whether they returned promptly to the front landing area.