Story highlights Donta Allen says he overheard an officer say, "Well, you know, we gave him a run for his money -- he's not breathing"

Allen was in the police van with Gray during part of the van's meandering course to the police station

"I know for a fact that he did not hurt himself," says Allen

(CNN) The man who rode in a police van with Freddie Gray -- separated only by a partition -- is adamant about two things:

"I know for a fact that he (Gray) did not hurt himself," Donta Allen, who was a fellow prisoner in the van during a portion of the meandering path of the vehicle after Gray was taken into the custody and before medical help was summoned, told CNN's Don Lemon in an interview. Reciting a litany of Gray's injuries, Allen added "you cannot do that (to yourself) in the paddy wagon. You can probably hit your head and have a little headache, but you can't hurt yourself to the point you're going to be dead."

And as for a report in the Washington Post that he told investigators he had heard noises indicating Gray was trying to injure himself, "untrue. Very, very, very untrue," said Allen.

During the interview, airing Friday on "CNN Tonight," Allen said at the police station, as he was being taken to the "bullpen" area for incoming prisoners, he overheard a female police officer say, "Well, you know, we gave him a run for his money -- he's not breathing."

"I don't know who, but I heard police saying that," Allen told Lemon. "They weren't saying it like, 'Guys, we really have a problem here.'"

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